Python-基礎
---
* shell腳本範例：
```
$ vi shell.sh
```
``` sh
1 ls
2 pwd
3 ls /
```
```
$ chmod u+x shell.sh
$ ll
-rwxrw-r-- 1 apple apple 12 1月 01 00:00 shell.sh // shell.sh 變成可執行檔
$ ./shell.sh // 執行shell.sh
shell.sh
/home/apple/Desktop
bin etc . . . .
boot home
etc .
cdrom .
data .
dev .
// 原本在ls pwd底下的功能也能在shell.sh使用!!!
```
* C 語言範例
`$ vi apple.c`
``` C
#include<studio.h>
int main(int argc,char ** argv)
{
printf("Hello,world"\n);
return 0;
}
```
* 編譯
```
$ ls
apple.c
$ gcc apple.c //編譯apple.c
$ ls
apple.c a.out
$ ./a.out
Hello,world
```
* 如果我想改成 "Hello你媽"?
`$ vi apple.c`
``` C
#include<studio.h>
int main(int argc,char ** argv)
{
printf("Hello你媽"\n);
return 0;
}
```
```
$ ./a.out
Hello,world // 竟然沒變？為何!!!因為沒有編譯
$ gcc apple.c
$ ./a.out
Hello你媽
* 綜上，C的運行過程：編輯>編譯>運行 (編輯完後編譯)
* Python 範例
`$ vi banana.py`
``` py
print("Hello,world")
```
```
$ python banana.py // 執行py : python 檔名
Hello, world
```
`$ vi banana.py`
``` py
print("Hello你媽")
```
```
$ python banana.py
Hello你媽
```
* 綜上，Python事實上是 編輯+編譯 > 運行 (編輯時同步編譯)
* 運行 python
`$ python 1.py(檔名)` : 運行 1.py
* python shell : 執行程式碼片段的 REPL 環境
``` Terminal
$ python or python3 # 使用 python2(3) 運行
>>> exit() # 離開
```
``` Terminal
$ ipython or ipthon3 # 使用 ipython(3) 運行，並支持Terminal 指令
In [1]: ls
apple.py
In [2]: exit # 離開
```
* 註釋
* 單行註釋 #
``` python
# Hello 你媽
print("Hello你媽") # Hello 你媽
```
* 多行註釋 ''' 或 """
``` python
''' 我是多行註釋，我超酷
今天天氣好
我愛Python
'''
```
``` python
""" 我真的超酷
今天天氣差
我不愛c
"""
```
* 如果 py 檔裡面有中文(包括註釋) `$ python`會無法運行
``` Terminal
$ vi apple.py
```
``` vim
1 # 輸出一些字
2 print("python 不讓我運行")
```
``` Terminal
$ python apple.py
File "hello_world.py", line 1
SyntaxError: Non-ASCII character '\xe8' in file hello_world.py on line 1, but no encoding declared; see http://python.org/dev/peps/pep-0263/ for details
$ python3 apple.py
python 不讓我運行
```
* 此時於開頭加入`#coding=utf-8` 或 `# -*- coding:utf-8 -*-`
``` Terminal
$ vi apple.py
```
``` python
1 # -*- coding:utf-8 -*-
2
3 '''# coding=utf-8'''
4
5 # 輸出一些字
6 print("python 不讓我運行")
```
``` Terminal
$ python apple.py
python 不讓我運行
```
變量 : 儲存數據
---
```python
apple_price = 35 # 定義了一個變量(apple_price),他的值是35(元)
apple_weight = 2.5 # 購買蘋果2.5(斤)
money = apple_price * apple_weight # 這也是一個變量,他的值就是price * weight
money = money - 10 # 首次出現才是變量，此時money已非首次出現，故非變量，而是給予已經存在的變量(money)賦上一個新的值
```
* input
```python
name = input("請輸入名字:") # 使用者輸入之內容將會賦予在name中
```
* python2 & python3 於 input("") 大不相同
* python2
```Terminal
$ python
>>> a = input("name:")
name:Ryan
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<string>", line 1, in <module>
NameError: name 'Ryan' is not defined
```
* python3
```Terminal
$ python3
>>> a = input("name:")
name:Ryan
>>> a
name:Ryan
```
* 原因：python2 將 `input()` 輸入的東西視為code而執行
```Terminal
$ python
>>> a = input("age:")
age:1+4
>>> a
5 # python3 的輸出結果會是 1+4
```
* 解決辦法：`a = raw_input()` -> python3沒有此Function，不過此Function的功能跟py3裡的 `input()`是一樣的
```Terminal
$ python
>>> a = raw_input()
1+4
>>> a
'1+4'
```
* `print()`
* 如果我想要輸出我的年齡
`$ vi print_age.py`
```python
age = 18
print("age")
```
```Terminal
$ python3 print_age.py
age
# 為何是age而非18呢!!!
# 因為print("")會打印出""裡面的字
```
`$ vi print_age.py`
```python
age = 18
print("age是:%d"%age) # %age會取age的值輸入到%d中
```
```Terminal
$ python3 print.py
age是:18
```
* 如果我想輸入名字？
`$ vi print_name.py`
```python
name = "大中天"
print("名字是:%d"%name)
```
```Terminal
$python3 print_name.py
Traceback (most recent call last):
File "print_name.py", line 2, in <module>
print("name:%d"%name)
TypeError: %d format: a number is required, not str
# %d不能放string
```
```python
# "" -> 係屬於String 不能使用%d，而需使用%s
# 故現在只需將 %d 改成 %s 即可
name = "大中天"
print("名字是:%s"%name)
```
```Terminal
$ python3 print_name.py
name:大中天
```
* Homework：打印一個名片
`$ vi print_business_card.py`
```python
# 輸入
name = input("name:")
phone_number = input("Phone number:")
address = input("address:")
# 輸出
print("==============")
print( "Name: %s" %name )
print( "Phone number: %s" %phone_number )
print( "Address: %s" %address )
print( "==============")
```
``` Terminal
$ python3 print_business_card.py
name:apple
Phone number:098764321
address:太麻里隔壁
==============
Name: apple
Phone number: 098764321
Address: 太麻里隔壁
==============
```
* 一次輸出多個
`vi print.py`
```python
name = "ryan"
age = 25
addr = "太麻里隔壁"
print("name:%s,age:%d,addr:%s"%(name, age, addr)) # 用,隔開, 並用()刮起來
```
```Terminal
python3 print.py
name:ryan,age:25,addr:太麻里隔壁
```
* ID 規則
* 由字母, _, 數字組成，數字不得當開頭
`a_1 = 1` 可以
`_a1 = 1` 可以
`1_a = 1` 不行，數字在開頭
`1!a = 1` 不行，有"!"
`1-a = 1` 不行，有"-"
* 可讀性
`a = 100` 這啥？
`appleprice = 100` 不好閱讀
`apple_prict = 100` 推薦
`applePrice = 100` 可以
`ApplePrice = 100` 可以
* keyword 不能使用
```Terminal
$ ipython3
In [1]: import keyword # 導入 keyword
In [2]: keyword.kwlist # keyword 的 list
Out[2]: ['False', 'None', 'True',...]
# 列出來的都不能用！
```
if 判斷語句
---
* 格式
``` python
if 條件:
條件成立時, Do something
```
`$ vi if.py`
```python=
age = 15
if age > 18:
print("Happy")
```
```Terminal
$ python3 vi if.py
# 條件沒有成立，print("Happy") 沒有被執行
```
`vi if.py`
``` python=
age = 20
if age > 18:
print("Happy")
```
```Terminal
$ python3 vi if.py
Happy # 條件成立，print("Happy") 被執行
```
* 運算符
* 比較運算符
```python
if a >= 3: # 如果 a≥3
print("")
```
|運算符|描述|
|:--:|:--:|
|>|>|
|<|<|
|==|=|
|>=|≥|
|<=|≤|
|!=|≠(較為通用)|
|<>|≠(py3不支援)|
* 邏輯運算符 and/ or/ not
``` python=
deposit = int(input("deposit:"))
hobbies = input("你愛喝茶嗎？(Y/N)")
sweet_and_ice_level = input("甜度冰塊？")
if deposit >= 25 and hobbies == "Y" and sweet_and_ice_level == "微微":
print("烏龍綠好喝")
else:
print("窮鬼沒品味")
```
|運算符|舉例|
|:-:|:-:|
|and|`if a >= 0 and a < 50`<br/>`print("50>a≥0")`|
|or|`if drink == "四季" or drink == "八冰綠"`<br/>`print("50嵐好喝")`|
|not|`if not (a >=0 and a < 50)`<br/>`print("a ≤ 0 or a > 50")`|
* 使用 input 的 if 問題
`$ vi if2.py`
```python=
age = input(age:)
if age > 18:
print("Happy")
```
```Terminal
$ python3 if2.py
age:19
Traceback (most recent call last):
File "if.py", line 3, in <module>
if age > 18:
TypeError: '>' not supported between instances of 'str' and 'int'
```
`vi if2.py`
```python=
age = input(age:) # input獲取的數據皆視為str age: > 19 > "19"
age_num = int(age) # 將age轉為 int
if age_num > 18: # 轉為int之後，兩者才有比較之可能
print("Happy")
```
```Terminal
$ python3 if2.py
age:20
Happy
```
* 變量類型
* Number
* int
* long
* float
* complex
* String
* List
* Tuble
* Dictionary
* Boolean
* 查詢類型 `$ type`
```Terminal
$ python3
>>>a = 1
>>>b = 1.1
>>>c = "1"
>>>
>>> type(a)
<class 'int'>
>>> type(b)
<class 'float'>
>>> type(c)
<class 'str'>
* if_else
`vi if2.py`
```python
age = input(age:) # input獲取的數據皆視為str age: > 19 > "19"
age_num = int(age) # 將age轉為 int
if age_num > 18: # 轉為int之後，兩者才有比較之可能
print("Happy")
else:
print("Unhappy") # 條件不滿足時，輸出 print("Unhappy")
```
```Terminal
$ python if2.py
age:15
Unhappy
```
* if_elif
```python=
num = int(input("請輸入數字(1-7)"))
if num == 1:
print("星期一")
elif num == 2:
print("星期二")
elif num == 3:
print("星期三")
elif num == 4:
print("星期四")
elif num == 5:
print("星期五")
elif num == 6:
print("星期六")
elif num == 7:
print("星期日")
else:
print("你智障嗎？")
```
while 循環
---
* 如果我想從1輸出到10
* 使用前面幾個學到的概念
```python=
print(1)
print(2)
# 或
num = 1
print(num)
num = num + 1
print(num)
# 一直重複？太麻煩了
```
* 使用 while
```python=
num = 1
while num <= 10: # 當 num≤10 時(條件滿足)，會循環執行，直到條件不滿足(num>10)止
print(num)
num = num + 1 # 這必須寫! 否則條件會永遠滿足，不停執行
```
嵌套(Nesting)
---
* if
```python=
ticket = 1 # 1:有買票 0:沒買票
knife_lenght = 3 #cm
if ticket == 1:
print("歡迎光臨，麻煩配合安檢")
if knife_lenght <= 5: # 當if ticket成立時，才會執行此判斷
print("歡迎光臨")
else:
print("沒票來這衝三小")
```
```python=
thirsty = input("Are you thirsty?(Y/N)")
if thirsty == "Y":
deposit = int(input("deposit:"))
hobbies = input("你愛喝茶嗎？(Y/N)")
sweet_and_ice_level = input("甜度冰塊？")
if deposit >= 25 and hobbies == "Y" and sweet_and_ice_level == "微微":
print("烏龍綠好喝")
else:
print("窮鬼沒品味")
else:
print("騙誰啊?")
```
* while
* Q. 減肥操
1. 站
2. 坐
3. 站
4. 轉五圈
5. 坐
```python=
sport = 1
while sport <= 10:
print("Stand")
print("Sit")
print("Stand")
cycle = 1
while cycle <= 5:
print("cycle")
cycle = cycle + 1
print("Sit")
sport = sport + 1
```
* Q. 輸出
1. \*
2. \**
3. \***
4. \****
5. \*****
```python=
# 我自己寫的
n = 1
while n<= 5:
print("*"*n)
n = n + 1
```
```python=
# 老師的寫法，看起來比較屌XD
i = 1
while i <= 5:
j = 1
while j <= i:
print("*", end="")
j+=1
print("")
i+=1
```
* Q.
1. \*****
2. \*****
3. \*****
4. \*****
5. \*****
```python=
# 我自己寫的
n = 1
while n <= 5:
print("*"*5)
n = n + 1
```
* `print("5", end="")`
``` python=
i = 1
while i <= 5:
j = 1
while j <=5:
# print 默認換行，要讓他不換行
print("*", end="")
j = j + 1
# 在c 語言中, 想讓 j加1的方式:
# j++; ++j; j+=1; j=j+1;
# 在python中，只有後兩種
# 以後都寫第三種!!!
print("")
i = i + 1 # i+=1
```
* 複合賦值運算符
|運算符|舉例|
|-|-|
|+=|a+=c 等於 a=a + c|
|-=|a-=c 等於 a=a - c|
|*=|a*=c 等於 a=a * c|
|/=|a/=c 等於 a=a / c|
|%=|a%=c 等於 a=a % c|
|**=|a**=c 等於 a=a ** c|
|//=|a//=c 等於 a=a // =c|
==注意==
```Terminal
$ python3
>>> a = 3
>>> a *= 3+9-10+23
>>> a
75
#他是 a = a * (3+9-10+23) = 3 * 25
#而非 a = a*3+9-10+23 = 31 !!!
```
* ==99_multiplication==
```python=
a = 1
while a <= 9:
b = 1
while b <= a:
print("%d*%d=%d \t"%(b,a,a*b),end="") # \t 相當於一個 tab ，可以達成對齊的效果
b += 1
print("")
a += 1
```
* ==Rock_paper_scissor==
```python=
# 導入random module
# Head_first p.30
import random
player = int(input("Enter:Rock(0) Paper(1) scissor(2)"))
computer = random.randiat(0,2)
# 執行很多組判斷時，用()隔開！！！
if (player==0 and computer==2) or (player==1 and computer==0) or (player==2 and computer==1):
print("Win")
elif player == computer:
print("Draw")
else:
print("Lose")
```
* Print("All even numbers between 1 and 100")
```python=
a = 1
while a<=100:
if a%2==0: # 如果a/2沒有餘數時
print(a)
a+=1
```
* ## break
`$ vi break.py`
```python=
a = 1
while a<=5:
print(a)
a+=1
if a == 3:
break # break 能立即結束while循環之執行
```
```Terminal
$ python3 break.py
1
2
```
`vi Twenty_1-100_even_numbers`
```python=
a = 1
num = 0
while a<=100:
if a%2==0:
print(a)
num+=1
if num == 20:
break
a+=1
```
* ## continue
`vi continue.py`
```python=
a = 1
while a<=5:
a+=1
print("----")
if a==3: # 如果a=3時
continue # 結束此次循環，直接執行下一次循環
print(a)
print("====")
```
```Terminal
$ python continue.py
----
2
----
----
4
----
5
----
6
====
```
for
---
```Terminal
$ ipython3
In [9]: a = "temporary"
In [10]: a
Out[10]: 'apple'
In [11]: for temp in a:
...: print(temp)
...:
a
p
p
l
e
# for 會對數據內容做循環
```
Int vs String
---
* [CPU](https://zh.wikipedia.org/wiki/%E4%B8%AD%E5%A4%AE%E5%A4%84%E7%90%86%E5%99%A8)
* 處理速度快
* 存取空間少
* [HDD](https://zh.wikipedia.org/wiki/%E7%A1%AC%E7%9B%98)
* 處理速度慢
* 存儲空間多
* 由於CPU大部分時間都在等待HDD的回應，為了提速而發展出[RAM](https://zh.wikipedia.org/wiki/%E9%9A%8F%E6%9C%BA%E5%AD%98%E5%8F%96%E5%AD%98%E5%82%A8%E5%99%A8)
* 速度與空間介於兩者間
* 1 G = 2^30^ = 1024 M
1 M = 2^20^ = 1024 K
1 K = 2^10^ = 1024 Byte
1 [Byte(B)](https://zh.wikipedia.org/wiki/%E5%AD%97%E8%8A%82) = 8 [bit(b)](https://zh.wikipedia.org/wiki/%E4%BD%8D%E5%85%83)
* bit是一種0與1的狀態，而Byte即可有 00000000, 00000001, 00000010, ..., 11111111 等 ==256== 種狀態( 2^8^ ), 故 1 Byte 可以表示的值為 0~255
```Terminal
In [1]: num = 100
In [2]: num2 = "100"
In [3]: # 最大的不同在於 100 可以存於 1 Byte (<255)
In [4]: # 而 "100" 係 "1" "0" "0" 分別存於 Byte，
In [5]: # 如果 Interpreter (解釋器) 係以 C 語言寫的，會再多一個 "\0"
In [6]: # 故 "100" 共花了 4 Byte 來存取
In [7]: int(num2) # 可以將num2的輸出轉成int
Out[7]: 100
In [8]: str(num) # 也可以將num轉成str
Out[8]: "100"
In [9]: len(num2) # 可以查看num2有多長
Out[9]: 3 # 事實上還有一個"\0", 但 python 不會算進去
```
* 加法
```Terminal
$ ipython3
In [1]: a = "壹佰"
In [2]: b = "塊"
In [3]: A = 10
In [4]: B = 90
In [5]: c = a + b
In [6]: c
Out[6]: '壹佰塊'
In [7]: C = A + B
In [8]: C
Out[8]: 100
In [9]: d = "===" + a + b + "==="
In [10]: d
Out[10]: '===壹佰塊==='
In [11]: e = "===%s==="%(a+b)
In [12]: e
Out[12]: '===壹佰塊==='
```
* Index
```Terminal
In [1]: name = "abcdefgh"
In [2]: name[3] # index 正數，從左至右
Out[2]: 'd'
In [3]: name[0] # index 從 0 開始!
Out[3]: 'a'
In [4]: name[8] # 超過範圍時會錯誤
IndexError: string index out of range
In [5]: len(name)
Out[5]: 8
In [6]: name[len(name)-1]
Out[6]: 'h'
In [7]: name[-1] # 負數即從右至左算起, 從 -1 開始
Out[7]: 'h'
In [8]: name[-2]
Out[8]: 'g'
```
* 切片
```Terminal
# [Start:End:步長]
In [1]: name = "abcdefgABCDEFG"
In [2]: name[2:5] # 始於 name[2]，終於 name[5] 的前一位(name[4])
Out[2]: 'cde' # e 是 name[4]
In [3]: name[2:-1] # 始於 name[2], 終於 name[-2]
Out[3]: 'cdefgABCDEF'
# 我想取至最後一位呢？name[2:0]?
In [4]: name[2:0]
Out[4]: '' # 空的!! 因為 index[0] 是 "a"
In [5]: name[2:] # 要取至最後一位就空著就行了
Out[5]: 'cdefgABCDEFG'
# 我想跳著取呢？
In [6]: name[2::2] # 步長就是一次走幾格
Out[6]: 'cegBDF'
In [7]: name[2::1]
Out[7]: 'cdefgABCDEFG' # 沒制定步長, 預設就是1
# 我想到著取呢? (逆序)
In [8]: name[::-1]
Out[8]: GFEDCBAgfedcba
```
List []
---
* 當我想存取多個數據時，且該數據類型相同， 定義多個變量並不實際， 此時List即派上用場
```Terminal
$ ipython3
In [1]: name = ["a", "b", "c"] # 定義了一個 List
In [2]: name
Out[2]: ['a', 'b', 'c']
# C 語言的數據: int num[]={1, 2, 3, 4, 5}
# 只能單一Type 定義
In [3]: name2 = [1, 0.1, "1"] # python 可同時定義不同Type的數據
# 增刪改查
# 增.append()
In [4]: name.append("d")
In [5]: name
Out[5]: ['a', 'b', 'c', 'd'] # append 會增加在 list 的 index[-1]
# 增.insert(位置, 內容)
In [6]: name.insert(0, "A") # 插入 "A" 於 index[0]
In [7]: name
Out[7]: ['A', 'a', 'b', 'c', 'd']
# 增.extend()
In [8]: name.extend(name2) # list + list
In [9]: name
Out[9]: ['A', 'a', 'b', 'c', 'd', 1, 0.1, "1"]
In [#]: # vs. append
In [#]: z = [1,2,3]
In [#]: x = [4,5]
In [#]: z.append(x)
In [#]: z
Out[#]:[1,2,3,[4,5]] # append會將整個列表當成一個整體加進來
# 刪.pop()
In [10]: name.pop() 刪除 index[-1]
Out[10]: ["1"]
# 刪.remove(內容)
In [11]: name.remove("A") # remove可指定內容刪除
In [12]: name
Out[12]: ['a', 'b', 'c', 'd', 1, 0.1]
In [13]: name.append("a")
In [14]: name
Out[14]: ['a', 'b', 'c', 'd', 1, 0.1, 'a']
In [15]: name.remove("a")
In [16]: name
Out[16]: ['b', 'c', 'd', 1, 0.1, 'a'] # .remove() 會從 index[0] 開始搜尋該內容，找到並刪除後即停止(只刪一次)
# 刪 del XXX[位置]
In [17]: del name[2]
In [18]: name
Out[18]: ['b', 'c', 1, 0.1, 'a']
# 改 xxx[位置] = 內容
In [19]: name[2] = "apple"
In [20]: name
Out[20]: ['b', 'c', 'apple', 0.1, 'a']
# 查 in / not in
In [21]: if "apple" in name:
...: print("找到了")
...:
找到了
In [22]: if "apple" not in name:
...: print("找不到")
...:
# 切片 [::]
In [23]: name[2:5]
Out[23]: ['apple', 0.1, 'a'] # 從list切片出來的內容還是list
In [24]: a = "abcdef"
In [25]: a[2:5]
Out[25]: 'cde' # 從字符串切片出來的東西還是字符串
```
* ==Name Managentment System== (modify)未完成
* 先完成框架
`$ vi name_managentment_system.py`
```python=
# print
print("="*10)
print("Names Managentment System")
print(" 1: append name ")
print(" 2: delete name ")
print(" 3: modify name ")
print(" 4: inquire name ")
print("="*10)
# input
num = int(input("Please input the function number: "))
# function
#append
if num==1:
pass # 不知道要寫啥時，先寫pass讓程式跳過這個指令
#delete
elif num==2:
pass
#modify
elif num==3:
pass
#inquier
elif num==4:
pass
else:
print("輸入有誤")
```
```Terminal
$ python3 names_management_system.py
==========
Names Managentment System
1: append name
2: delete name
3: modify name
4: inquire name
==========
Please input the function number: 1
$ python3 names_management_system.py
==========
Names Managentment System
1: append name
2: delete name
3: modify name
4: inquire name
==========
Please input the function number: 7
輸入有誤
```
* 完成 append function
`$ vi name_managentment_system.py`
```python=10
# input
num = int(input(" Please input the function number: "))
names = [] # 建立一個空的list
# function
#append
if num==1:
append_name = input("Append name: ")
names.append(append_name)
print(names)
```
```Terminal
$ python3 name_managentment_system.py
==========
Please input the function number: 1
Append name: a
['a']
$
# 每輸入一次就退出程序，因為if判斷完即完成指令
```
`$ vi name_managentment_system.py`
```python=10
# 讓程序不停重複迴圈
while True: # 下面註解
# input
num = int(input(" Please input the function number: "))
names = [] # 建立一個空的list
# function
#append
if num==1:
append_name = input("Append name: ")
names.append(append_name)
print(names)
#delete
elif num==2:
pass
#modify
elif num==3:
pass
#inquier
elif num==4:
pass
else:
print("輸入有誤")
```
```Terminal
# while True 註解
$ ipython3
In [1]: a = 10
In [2]: if a>5:
...: pass
...:
In [3]: a>5
Out[3]: True # 條件成立
In [4]: a<5
Out[4]: False # 條件不成立
```
```Terminal
$ python3 name_managentment_system.py
==========
Please input the function number: 1
Append name: a
['a']
Please input the function number: 1 # 沒有直接結束程序了，因為會持續迴圈
Append name: b
['b'] # 竟然不是 ['a', 'b'] ?
# 因為 names = [] 也在迴圈內，每迴圈一次 name就重置回空list
```
`$ vi name_managentment_system.py`
```python=10
names = [] # 建立一個空的list
# 讓程序不停重複迴圈
while True:
# input
num = int(input(" Please input the function number: "))
```
```Terminal
$ python3 name_managentment_system.py
==========
Please input the function number: 1
Append name: a
['a']
Please input the function number: 1
Append name: b
['a', 'b']
```
* 完成其他 Function
`$ vi name_managentment_system.py`
```python=17
# function
#append
if num==1:
append_name = input("Append name: ")
names.append(append_name)
print(names)
#delete
elif num==2:
remove_name = input("Delete name: ")
names.remove(remove_name)
print(names)
#modify 還沒想到怎麼解，因為modify需要知道index
elif num==3:
pass
#inquier
elif num==4:
inquier_name = input("Inquier name: ")
if inquier_name in names:
print("有")
else:
print("沒有")
else:
print("輸入有誤")
```
```Terminal
$ python name_managentment_system.py
==========
Please input the function number: 1
Append name: a
['a']
Please input the function number: 1
Append name: b
['a', 'b']
Please input the function number: 1
Append name: c
['a', 'b', 'c']
Please input the function number: 2
Delete name: b
['a', 'c']
Please input the function number: 4
Inquier name: a
有
Please input the function number: 4
Inquier name: d
沒有
```
* 新增離開功能
`$ vi names_management_system.py`
```python=
# print
print("="*10)
print("Names Managentment System")
print(" 1: append name ")
print(" 2: delete name ")
print(" 3: modify name ")
print(" 4: inquire name ")
print(" 5: end")
print("="*10)
names = [] # 建立一個空的list
# 讓程序不停重複迴圈
while True:
# input
num = int(input("Please input the function number: "))
# function
#append
if num==1:
append_name = input("Append name: ")
names.append(append_name)
print(names)
#delete
elif num==2:
remove_name = input("Delete name: ")
names.remove(remove_name)
print(names)
#modify 還沒想到怎麼解，因為modify需要知道index
elif num==3:
pass
#inquier
elif num==4:
inquier_name = input("Inquier name: ")
if inquier_name in names:
print("有")
else:
print("沒有")
#end
elif num==5:
break
else:
print("輸入有誤")
```
```Terminal
$ python3 names_management_system.py
Please input the function number: 5
$
```
Dictionary {}
---
當我想存取多種不同類型的數據，也許Dictionary是個好選擇
* ## vs List
```Terminal
$ ipython3
In [1]: a = [1, "a", "b"]
In [2]: print("%s, %d, %s"%(a[1], a[0], a[-1]))
a , 1, b
# list 要查詢時需要知道 Index，要列出來一一數在第幾個位置，如果list資料有一萬筆呢？
#dict = {Key: Value}
In [3]: b = {"a":"apple", "b":"book", "c":"car"}
In [4]: print("%s, %s, %s"%(b["a"], b["b"], b["c"])
apple, book, car
#dirt 可以輸入指定的key來輸出資訊
```
* 增刪改查
```Terminal
$ ipython3
In [1]: a = {"a":1, "b":2, "c":"C", "d":"D"}
# 增，改 xxx[key] = value
In [2]: a["e"] = "E" # []沒有在dict裡時，則會新增
In [3]: a
Out[3]: {'a': 1, 'b': 2, 'c': 'C', 'd': 'D', 'e'= 'E'}
In [4]: a['c'] = 3 # []有在dict裡時，則會修改
In [5]: a
Out[5]: {'a': 1, 'b': 2, 'c': 3, 'd': 'D', 'e'= 'E'}
# 刪 del xxx[key]
In [6]: del a["e"]
In [7]: a
Out[7]: {'a': 1, 'b': 2, 'c': 3, 'd': 'D'}
# 查 xxx.get(key)
In [8]: a.get("a")
Out[8]: 1 # 如果有的話就會顯示他的 value
In [9]: a.get("e") # 沒有"e"的key，所以也就沒有對應的value
```
* 常見功能
```Terminal
$ ipython3
In [#]: a = {"a":1, "b":"B"}
In [#]: a.get("a")
Out[#]: 1
In [#]: if "a" in a:
...: print("有")
...:
有
In [#]: len(a)
Out[#]: 2
In [#]: a.keys()
Out[#]: dict_keys(['a', 'b'])
In [#]: for temp in a.keys():
...: print(temp)
...:
a
b
In [#]: a.values()
Out[#]: dict_values([1, 'B'])
In [#]: for temp in a.values():
...: print(temp)
...:
1
B
In [#]: a.items()
Out[#]: dict_items([('a', 1), ('b', 'B')]) # 注意！他將 key 跟 value 裝進 tuple 裡
In [#]: for temp in a.items():
...: print(temp)
...:
('a', 1)
('b', 'B')
# 畢竟 tuple 只能查閱，如果我想增改刪，可以取他的值出來輸出
In [#]: for temp in a.items():
...: print("key=%s, vaule=%s"%(temp[0], temp[1]))
...:
key=a, value=1
key=b, value=B
# 另種寫法
In [#]: for a,b in a.items():
...: print("key=%s, value=%s"%(a,b))
...:
key=a, value=1
key=b, value=B # 下開註解
```
```Terminal
$ ipython3
In [#]: a = (1,2)
In [#]: x,z = a
In [#]: x
Out[#]: 1
In [#]: z
Out[#]: 2
```
* ==Business_Card==
`$ vi business_card_managentment_system.py`
```python=
# print
print("="*10)
print(" 1.append")
print(" 2.delete")
print(" 3.modify")
print(" 4.inquire")
print(" 5.end")
print("="*10)
# 需要一個列表來存取所有名片
business_card = []
while True:
# input
num = int(input("請輸入功能數字: "))
# function
if num == 1:
pass
elif num == 2:
pass
elif num == 3:
pass
elif num == 4:
pass
elif num == 5:
break
else:
print("輸入有誤")
```
`$ vi business_card_managentment_system.py`
```python=19
if num == 1:
new_name = input("name:")
new_phone = input("phone:")
new_addr = input("address:")
new_info = {}
new_info["name"] = new_name
new_info["phone"] = new_phone
new_info["addr"] = new_addr
business_card.append(new_info)
print(business_card)
```
```Terminal
$ python3 business_card_managentment_system.py
請輸入功能數字: 1
name:a
phone:a
address:a
[{'name': 'a', 'phone': 'a', 'addr': 'a'}]
請輸入功能數字: 1
name:b
phone:b
address:b
[{'name': 'a', 'phone': 'a', 'addr': 'a'}, {'name': 'b', 'phone': 'b', 'addr': 'b'}]
```
* 新增一個功能：顯示所有名片
`$ vi business_card_managentment_system.py`
```python=
# print
print("="*10)
print(" 1.append")
print(" 2.delete")
print(" 3.modify")
print(" 4.inquire")
print(" 5.顯示所有名片")
print(" 6.end")
print("="*10)
```
```python=37
elif num == 5:
for temp in business_card:
print(temp)
elif num == 6:
break
```
```Terminal
$ python business_card_managentment_system.py
請輸入功能數字: 1
name:a
phone:1
address:1
[{'name': 'a', 'phone': '1', 'addr': '1'}]
請輸入功能數字: 1
name:b
phone:1
address:1
[{'name': 'a', 'phone': '1', 'addr': '1'}, {'name': 'b', 'phone': '1', 'addr': '1'}]
請輸入功能數字: 5
{'name': 'a', 'phone': '1', 'addr': '1'}
{'name': 'b', 'phone': '1', 'addr': '1'}
```
* 讓名片顯示更人性化些，且讓輸入功能前空一行
`$ vi business_card_managentment_system.py`
```python=37
elif num == 5:
print("name\tphone\taddr") #\t 對齊
for temp in business_card: #下面註解
print("%s\t%s\t%s"%(temp["name"], temp["phone"], temp["addr"]))
elif num == 6:
break
else:
print("輸入有誤")
print("") # 空一行
```
```Terminal
# for in 註解
$ ipython3
In [1]: a = [{"a":"A", "b":1}, {"a":"C", "b":2}]
In [2]: for temp in a:
...: print(temp)
...:
{'a': 'A', 'b': 1}
{'a': 'C', 'b': 2} # for會循環一次[]裡的元素
In [3]: for temp in a:
...: print(temp["a"]) # 只輸出"a"的value
...:
...:
A
C
```
```Terminal
$ python3 business_card_managentment_system.py
請輸入功能數字: 1
name:a
phone:a
address:a
[{'name': 'a', 'phone': 'a', 'addr': 'a'}]
請輸入功能數字: 1
name:b
phone:b
address:b
[{'name': 'a', 'phone': 'a', 'addr': 'a'}, {'name': 'b', 'phone': 'b', 'addr': 'b'}]
請輸入功能數字: 5
name phone addr
a a a
b b b
```
`vi business_card_managentment_system.py`
```python=38
elif num == 4:
find_name = input("name: ")
for temp in business_card:
if find_name == temp["name"]:
print("%s\t%s\t%s"%(temp["name"], temp["phone"], temp["addr"]))
else:
print("查無此人")
```
```Terminal
$ python business_card_managentment_system.py
請輸入功能數字: 1
name:a
phone:a
address:a
[{'name': 'a', 'phone': 'a', 'addr': 'a'}]
請輸入功能數字: 1
name:b
phone:b
address:b
[{'name': 'a', 'phone': 'a', 'addr': 'a'}, {'name': 'b', 'phone': 'b', 'addr': 'b'}]
請輸入功能數字: 5
name phone addr
a a a
b b b
請輸入功能數字: 4
name: a
a a a
查無此人
請輸入功能數字: 4
name: b
查無此人
b b b
請輸入功能數字: 4
name: c
查無此人
查無此人
# 那麼多查無此人是三小
# 因為for找a時，第一圈有找到a 所以輸出a的資料，然後又繼續第二圈(b)，所以多了一個查無此人！bc亦同
# 解決辦法：找到後，break結束循環？
# 但這樣只能解決a(a第一圈就找到而跳出)，bc一樣會有查無此人
# 大絕招！直接給予 True / False
```
`vi business_card_managentment_system.py`
```python=38
elif num == 4:
find_name = input("name: ")
flag = False # 在for之前先設一個標記為錯誤
for temp in business_card:
if find_name in temp["name"]:
print("%s\t%s\t%s"%(temp["name"], temp["phone"], temp["addr"]))
flag = True # 當有找到時，標記為正確
#break (沒有意義，True就出去了)
if flag == False:
print("查無此人")
```
```Terminal
$ python3 business_card_managentment_system.py
請輸入功能數字: 1
name:a
phone:a
address:a
[{'name': 'a', 'phone': 'a', 'addr': 'a'}]
請輸入功能數字: 1
name:b
phone:b
address:b
[{'name': 'a', 'phone': 'a', 'addr': 'a'}, {'name': 'b', 'phone': 'b', 'addr': 'b'}]
請輸入功能數字: 5
name phone addr
a a a
b b b
請輸入功能數字: 4
name: a
a a a
請輸入功能數字: 4
name: b
b b b
請輸入功能數字: 4
name: c
查無此人
```
* 最後把用拿測試的print(business_card)標記掉
```python=
# print
print("="*10)
print(" 1.append")
print(" 2.delete")
print(" 3.modify")
print(" 4.inquire")
print(" 5.end")
print("="*10)
# 需要一個列表來儲存名片
business_card = []
while True:
# input
num = int(input("請輸入功能數字: "))
# function
if num == 1:
new_name = input("name:")
new_phone = input("phone:")
new_addr = input("address:")
new_info = {}
new_info["name"] = new_name
new_info["phone"] = new_phone
new_info["addr"] = new_addr
business_card.append(new_info)
#test(print(business_card))
elif num == 2: # 還沒想到怎麼刪整個{}
pass
elif num == 3:
pass
elif num == 4:
find_name = input("name: ")
flag = False
for temp in business_card:
if find_name == temp["name"]:
print("%s\t%s\t%s"%(temp["name"], temp["phone"], temp["addr"]))
flag = True
#break
if flag == False:
print("查無此人")
elif num == 5:
print("name\tphone\taddr")
for temp in business_card:
print("%s\t%s\t%s"%(temp["name"], temp["phone"], temp["addr"]))
elif num == 6:
break
else:
print("輸入有誤")
print("") # 空一行
```
Traversal ( while & for, 台灣: [尋訪](http://alrightchiu.github.io/SecondRound/binary-tree-traversalxun-fang.html); 中國: [遍歷](https://zh.wikipedia.org/wiki/树的遍历) )
---
```Terminal
$ ipython3
In [1]: a = [1,2,3,4,5,6,7]
In [2]: for temp in a:
...: print(temp)
...:
1
2
3
4
5
6
7
In [3]: a_lenght = len(a)
In [4]: i = 0
In [5]: while i<a_lenght:
...: print(a[i])
...: i+=1
1
2
3
4
5
6
7
```
for_else (只有python可以)
---
```Terminal
$ ipython3
In [1]: a = [1,2,3,4,5]
In [2]: for temp in a:
...: print(temp)
...: else:
...: print(6)
...:
1
2
3
4
5
6
# for 會先循環完再執行else
In [3]: b = []
In [4]: for temp2 in b:
...: print(temp2)
...: else:
...: print(6)
...:
6
# for一樣有執行循環，只是內容是空的，循環玩執行else
In [5]: for temp in a:
...: print(temp)
...: break
...: else:
...: print(6)
...:
1
# break跳出後，else就沒有再執行了
```
`vi for_else.py`
```python=
# 名片系統找人的另種寫法
a = [{"name":"a", "age":18},{"name":"b", "age":20}]
while True:
find_name = input("name: ")
for temp in a:
if find_name == temp["name"]:
print(temp)
break
# if 成立時輸出資料，然後直接跳出，就不會執行 else
# 如果 if 一直到 for 循環完都沒有成立，就沒有任何輸出，也沒有觸發到 break
# 然後就能接著執行 else
else:
print("查無此人")
```
```Terminal
$ python3 for_else.py
name: a
a 18
name: b
b 20
name: c
查無此人
```
Tuple ()
---
Tuple只能查，增刪改都不行
Function
---
把具有獨立功能的代碼塊當作一個整體，該整體即為一個Function
`vi def_定義並調用函數.py`
```python=
# 定義函數
def print_card():
print("="*50)
print(" Business Card Managentment System ")
print(" 1.Name")
print(" 2.Addr")
print(" 3.Phone")
print("="*50)
def print_triangle():
i = 1
while i <= 5:
j = 1
while j <= i:
print("*",end="")
j+=1
print("")
i+=1
# 調用函數
print_card()
print_triangle()
```
`vi def_帶有參數的函數.py`
```python
def sum_2_number(a,b): # 直接把變量放到裡面
#a = 1
#b = 2
result = a + b
print("%d + %d = %d"%(a, b, result)) # 1 + 2 = 3
num1 = int(input("請輸入第一個數字："))
num2 = int(input("請輸入第二個數字："))
sum_2_number(num1, num2) # 調用函數時，賦予變量
```
Return的作用-獲取溫度
---
`$ vi return_value_function.py`
```python=
def get_temperature_Celsius():
temperature_Celsius = 22
print("當前的攝氏溫度是：%d"%temperature_Celsius)
def get_temperature_Fahrenheit():
temperature_Fahremheit = temperature_Celsius*9/5+32
print("當前的華氏溫度是：%d"%temperature_Fahremheit)
get_temperature_Celsius()
get_temperature_Fahrenheit()
# temperature_Fahremheit = temperature_Celsius*9/5+32
# NameError: name 'temperature_Celsius' is not defined
# 兩個函數的值不能互相流通
```
`$ vi return_value_function.py`
```python=
def get_temperature_Celsius():
temperature_Celsius = 22
print("當前的攝氏溫度是：%d"%temperature_Celsius)
return temperature_Celsius # 1.將 temperature_Celsius 的值回傳 -> get_temperature_Celsius() = 22
def get_temperature_Fahrenheit(temperature_Celsius): # 4.指定參數
temperature_Fahremheit = temperature_Celsius*9/5+32
print("當前的華氏溫度是：%d"%temperature_Fahremheit)
result = get_temperature_Celsius() # 2.定義變量
get_temperature_Fahrenheit(result) # 3.賦予變量
```
多個 Return
---
`vi return2_一個函數中有多個return.py`
```python=
def test():
a = 1
b = 2
c = 3
return a
return b
return c
num = test()
print(num)
# python3 return2_一個函數中有多個return.py
# 1
# 只有回傳a!
# 因為return會結束function
# 所以return a之後的就都沒有被執行到
```
`vi return2_一個函數中有多個return.py`
```python=
# 解決辦法: 把value包起來傳回去
def test():
a = 1
b = 2
c = 3
d = [a,b,c]
return d
#return a
#return b
#return c
num = test()
print(num)
```
異常處理
---
```python
print(num)
print("--1--")
```
```$
NameError: name 'num' is not defined
```
- 當上面異常時, 直接就結束程序, 導致下面無法執行
- try
```python
try:
print(num)
except NameError: # NameError 打印 -1-
print("-1-")
print("-2-")
```
```$
-1-
-2-
```
```python
try:
#print(num)
open("xxx.txt")
except NameError:
print("-1-")
except FileNotFoundError:
print("-3-")
# except (NameError, FileNotFoundError):
# print("-4-")
# 兩句合一, 元祖
print("-2-")
```
```$
-3-
-2-
```
- Exception
```python
try:
11/0
except (NameError, FileNotFoundError):
print("-1-")
# 異常是其他的: Exception
# as 把異常return出來, 沒有需要就不用寫
except Exception as ret:
print(ret)
# python2的其他異常表示
# except: -> 沒有Exception
print("-2-")
```
- else, finally
```python
try:
11/0
except (NameError, FileNotFoundError):
print("-1-")
except Exception as ret:
print(ret)
else: # 沒有異常的話輸出-3-
print("-3-")
finally: # 不論有無異常, 最後都輸出-4-
print("-4-")
print("-2-")
```
- 異常傳遞
```python
def test1():
try:
test2()
except Exception:
print("-1-")
def test2():
print(num)
test1()
```
- 自定義異常
```python
class xxx(Exception): # Exception 所有異常的父類
def __init__(self, length, atleast):
self.length = length
self.atleast = atleast
try:
psw = input("password:(至少三個半形)")
if len(psw)<3:
raise xxx(len(psw), 3)
except xxx as ret:
print("你只輸入%d, 至少要%d個啦"%(ret.length, ret.atleast))
```
- 異常處理拋出異常
```python
class xxx(object):
def __init__(self, switch):
self.switch = switch
def xxxx(self, a, b):
try:
a/b
except Exception as ret:
if self.switch:
print(ret)
else:
# 把異常丟還給系統
raise
t = xxx(True)
t.xxxx(11,0)
print("---")
t = xxx(False)
t.xxxx(11,0)
# 應用:
# 寫LOG日誌, 有意義的異常寫下來, 沒意義的惡意攻擊就丟還給系統處理
```
```$
division by zero
---
ZeroDivisionError: division by zero
```
Python3' Note
===
* 可變類型: List, Dict
* 不可變類型: Num, Str, Tuple
* [Hash function](https://zh.wikipedia.org/wiki/散列函數)
```python3=
In [xx]: a = {[a]:123}
TypeError: unhashable type: 'list'
```
* 為避免使用者更改 key 而造成 key 與 Hash Value 無法對應，
* 故 key 不得使用可變類型
[遞歸(Recursion)](https://zh.wikipedia.org/wiki/递归)
---
* 欲完成[階乘](https://zh.wikipedia.org/wiki/階乘)運算 4!
* 想法一：4! = 4\*3\*2*1
```python
i = 1
num = 1
while i<5:
num *=i
i+=1
print(num)
```
* 想法二: 4! = 4 * 3!
```python
'''概念：
def xxxx(num):
num * xxxxx(num-1)
def xxx(num):
num * xxxx(num-1)
def xx(num):
num * xxx(num-1)
xx(4)
每次都乘自己-1的結果
'''
# 實現
def getnum(num):
if num>1:
return num * getnum(num-1)
else:
return num
result = getnum(4)
print(result)
'''
運作:
getnum(4) = 4 * getnum(3) = 4 * 6
getnum(3) = 3 * getnum(2) = 3 * 2
getnum(2) = 2 * getnum(1) = 2 * 1
getnum(1) = 1
'''
# 使用遞歸時注意: 避免死循環
# 運作死循環的函數時，執行到某一次程式時就會崩潰
# 因為內存外溢
```
匿名函數
---
* 一般函數
```python
def test(a,b):
# a+b
return a+b
result1 = test(1,2)
print("result=%d"%result1)
# TypeError: %d format: a number is required, not NoneType
# 要回傳，否則會報錯
```
* 匿名函數
```python
# 變量 = lambda 參數:式子
c = lambda a,b:a+b
# 調用匿名函數
result2 = c(1,2)
print("result=%d"%result2)
```
* 兩者區別
* 區別標準: 匿名函數自帶 return
* 區別實益:
* 一般函數用來寫較複雜的東西,
* 匿名函數則寫較簡易的東西(如計算).
匿名函數應用
---
```python
In [xx]: apple = [1,2,3,5,3,23,2,25,235,4,234]
In [xx]: apple.sort()
In [xx]: apple
Out[xx]: [1, 2, 2, 3, 3, 4, 5, 23, 25, 234, 235]
# sort 按大小排序
In [xx]: a = [{"a":"A", "b":22}, {"a":"B", "b":19}, {"a":"C", "b":20}]
In [xx]: a.sort()
TypeError: '<' not supported between instances of 'dict' and 'dict'
In [xx]: a.sort(key= lambda x:x["b"])
# 指定 key 的參數為 x,
# 亦即 x 有 "a" 跟 "b"
# 接著取 "b" 的 value 出來就能比較了
In [xx]: a
Out[xx]: [{'a': 'B', 'b': 19}, {'a': 'C', 'b': 20}, {'a': 'A', 'b': 22}]
```
匿名函數應用2
---
```python
# 舊寫法
def test(a,b):
result = a+b
print("Result1=%s"%result)
# 新寫法
def test2(a,b,func):
result = func(a,b)
print("Result2=%s"%result)
test(1,2)
test2(1,2, lambda x,y:x+y)
test2(1,2, lambda x,y:x-y)
# 優點: 讓test function更彈性，而不會侷限在一個功能
```
匿名函數應用2延伸
---
```python
# coding=utf-8
def test(a,b,func):
result = func(a,b)
print("Result=%s"%result)
new_func = input("請輸入一個匿名函數: ")
test(1,2,new_func)
'''Terminal
$ python2 匿名函數應用延伸.py
請輸入一個匿名函數: lambda x,y:x+y+100
Result=103
$ python3 0511_匿名函數應用延伸.py
請輸入一個匿名函數: lambda x,y:x+y+100
TypeError: 'str' object is not callable
'''
# python3 的 input 會將輸入數據視為一個str
# 解決辦法: eval
```
```python
# coding=utf-8
def test(a,b,func):
result = func(a,b)
print("Result=%s"%result)
new_func = input("請輸入一個匿名函數: ")
new_func = eval(new_func)
test(1,2,new_func)
'''Terminal
$ python3 匿名函數應用延伸.py
請輸入一個匿名函數: lambda x,y:x+y+100
Result=103
'''
```
補充知識點_可變與不可變
---
```python
a = 100
b = [100]
c = [100]
def test(num):
num+=num
print(num)
def test2(num):
num = num + num
print(num)
test(a)
print(a)
print("---")
test(b)
print(b)
print("---")
test2(c)
print(c)
'''Terminal
200
100
# 遇到不可變時(a,num), 會直接創一個新的變量來儲存(局部變量)
---
[100, 100]
[100, 100]
# 遇到可變時(b,list), 就會直接改(全局變量)
---
[100, 100]
[100]
# num+=num ≠ num=num+num
# num=num+num 是另 num 指向了一個新的id(num+num),而非原本的c
# 故 c 沒被修改
'''
```
補充知識點_交換兩個變量
---
```python
a = 6
b = 4
'''方法一
c = 0
c = a
a = b
b = c
'''
'''方法二
a = a+b
b = a-b
a = a-b
'''
# 方法三
a,b = b,a
print(a,b)
```
str常見操作
---
```python
In [1]: mystr = "dog is dog,not cat."
In [2]: mystr.find("mouse")
Out[2]: -1
In [3]: mystr.find("dog")
Out[3]: 0
In [4]: mystr.find("cat")
Out[4]: 15
In [5]: mystr.index("mouse")
ValueError: substring not found
In [6]: mystr.index("dog")
Out[6]: 0
In [7]: mystr.index("cat")
Out[7]: 15
In [8]: mystr.rfind("dog")
Out[8]: 7
In [9]: mystr.rindex("dog")
Out[9]: 7
In [10]: mystr.count("dog")
Out[10]: 2
In [11]: mystr.count("doggie")
Out[11]: 0
# replace (old, new, count)
In [12]: mystr.replace("is","IS")
Out[12]: 'dog IS dog,not cat.'
In [13]: mystr
Out[13]: 'dog is dog,not cat.'
# str 不可變，故mystr沒有真的被改變，是指向另一個id，
# 如欲保存, 需另用一個變量將其存下
In [14]: mystr.replace("dog","DOG")
Out[14]: 'DOG is DOG,not cat.'
In [15]: mystr.replace("dog","DOG",1)
Out[15]: 'DOG is dog,not cat.'
In [16]: mystr.replace("dog","DOG",2)
Out[16]: 'DOG is DOG,not cat.'
# split(sep=None, maxsplit=-1)
In [19]: mystr.split(" ")
Out[19]: ['dog', 'is', 'dog,not', 'cat.']
In [24]: mystr.split(" ", 2)
Out[24]: ['dog', 'is', 'dog,not cat.']
In [56]: mystr.partition("not")
Out[56]: ('dog is dog,', 'not', ' cat.')
In [57]: mystr.partition("dog")
Out[57]: ('', 'dog', ' is dog,not cat.')
In [58]: mystr.rpartition("dog")
Out[58]: ('dog is ', 'dog', ',not cat.')
In [59]: test2 = "123\n1233234\nasdhjwhkjq\nfdhfjkhfd\n123sff2"
In [61]: test2.splitlines()
Out[61]: ['123', '1233234', 'asdhjwhkjq', 'fdhfjkhfd', '123sff2']
# capitalize & title
In [29]: mystr.capitalize()
Out[29]: 'Dog is dog,not cat.'
In [31]: mystr.title()
Out[31]: 'Dog Is Dog,Not Cat.'
# startswith
In [34]: child_name = "Wang xxx"
In [35]: child_name.startswith("Wang")
Out[35]: True
In [36]: child_name.startswith("li")
Out[36]: False
# endswith
# 應用: 查檔案類型
In [37]: file_name = "xxx.txt"
In [38]: file_name.endswith("txt")
Out[38]: True
In [39]: file_name.endswith("tnt")
Out[39]: False
# isalpha 判斷str是否為純字母
In [63]: a = "fjkhjkwqhjkh"
In [64]: a.isalpha()
Out[64]: True
In [65]: a = "fjkhjkwqhjkh1"
In [66]: a.isalpha()
Out[66]: False
# isdigit 判斷str是否為純數字
In [70]: b = "123"
In [71]: b.isdigit()
Out[71]: True
'''應用舉例情境
In [75]: num = int(input("請輸入功能數字:"))
請輸入功能數字:1ab
ValueError: invalid literal for int() with base 10: '1ab'
# 用戶如果不是輸入數字，程式就掛了
# 解決辦法: 先判斷用戶是不是輸入你要的再轉，用戶亂輸就print("徹幹礁")
'''
# isalnum 判斷str是不數字與字母組成
# 常用於帳號密碼組成判斷
In [76]: c = "1223fskdjfk"
In [77]: c.isalnum()
Out[77]: True
In [80]: c = "123 jfdks"
In [81]: c.isalnum()
Out[81]: False
# isspace
In [1]: a = " "
In [2]: a.isspace()
Out[2]: True
In [3]: a = " _ "
In [5]: a.isspace()
Out[5]: False
# upper 將所有字都變成大寫
In [xx]: exit_flag = "Yes"
In [42]: exit_flag.upper()
Out[42]: 'YES'
# lower 將所有字都變成小寫
In [43]: exit_flag.lower()
Out[43]: 'yes'
# 應用舉例情境: 如欲使用戶輸入yes來退出程式, 此時用戶可能輸入的yes可能有好幾種(YES,yes,Yes...)
# 解決方法一: 每一種都寫一段程式碼來退出
# 解決方法二: 使用upper / lower 來統一變成大寫/ 小寫
In [44]: lyric = "腦海有風, 髮膚無損."
In [48]: lyric.center(20)
Out[48]: ' 腦海有風, 髮膚無損. '
In [49]: lyric.ljust(20)
Out[49]: '腦海有風, 髮膚無損. '
In [50]: lyric.rjust(20)
Out[50]: ' 腦海有風, 髮膚無損.'
# strip 砍空格
In [51]: test = lyric.center(20)
In [52]: test
Out[52]: ' 腦海有風, 髮膚無損. '
In [53]: test.strip()
Out[53]: '腦海有風, 髮膚無損.'
In [54]: test.lstrip()
Out[54]: '腦海有風, 髮膚無損. '
In [55]: test.rstrip()
Out[55]: ' 腦海有風, 髮膚無損.'
# join 在每個str中插入指定的str, 形成一個新的str
In [6]: names = ["apple", "banana", "cow"]
In [7]: a = "_"
In [8]: a.join(names)
Out[8]: 'apple_banana_cow'
# Q
# a = "fdhjsfh sdkjfl\n\n\n jdsf wklj \t\t\t kqjk jkl jla j lkjlkqjrlk "
# 欲將 a 的 "space" "\t" "\n" 給砍了
In [10]: a = "fdhjsfh sdkjfl\n\n\n jdsf wklj \t\t\t kqjk jkl jla j lkjlkqjrlk "
In [11]: a.split()
Out[11]: ['fdhjsfh', 'sdkjfl', 'jdsf', 'wklj', 'kqjk', 'jkl', 'jla', 'j', 'lkjlkqjrlk']
In [12]: b = " "
In [13]: b.join(a.split())
Out[13]: 'fdhjsfh sdkjfl jdsf wklj kqjk jkl jla j lkjlkqjrlk'
```
讀寫文件
===
```python
In [16]: f = open("haha.txt")
FileNotFoundError: [Errno 2] No such file or directory: 'haha.txt'
In [17]: f = open("haha.txt", "w")
In [18]: f.write("haha")
Out[18]: 4
In [19]: f.close() # 寫完記得關起來
In [20]: f = open("haha.txt")
# 沒有報錯 ->已有 haha.txt 可以讀
In [22]: f.read(1)
Out[22]: 'h'
In [23]: f.read(1)
Out[23]: 'a'
In [24]: f.read(1)
Out[24]: 'h'
In [25]: f.read(1)
Out[25]: 'a'
In [26]: f.read(1)
Out[26]: ''
In [27]: f.read(1)
Out[27]: ''
# read 會從上次讀取的地方繼續往後讀
In [29]: f.close() # 讀完記得關起來
```
`vi 隨便寫寫.py`
```python
f = open("hahaha.txt", "w")
f.write("哈哈哈")
f.close()
'''Terminal
$ python3 隨便寫寫.py
$ ls
隨便寫寫.py hahaha.txt
'''
```
`vi 讀取隨便寫寫.py`
```python
f = open("hahaha.txt", "r")
content = f.read()
print(content)
f.close()
'''Terminal
$ python3 讀取隨便寫寫.py
哈哈哈
'''
```
`vi 複製檔案.py`
```python=
old_file_name = input("請輸入欲複製的文件名(含檔名): ")
f_read = open(old_file_name, "r")
content = f_read.read()
new_file = open("xxxx.txt", "w")
new_file.write(content)
f_read.close()
new_file.close()
'''Terminal
$ 複製檔案.py
請輸入欲複製的文件名(含檔名): hahaha.txt
$ ls
隨便寫寫.py 複製檔案.py hahaha.txt xxxx.txt
$ cat xxxx.txt
哈哈哈
'''
# 檔名有點問題
```
`vi 複製檔案.py`
```python=5
# new_file = open("xxxx.txt", "w")
new_file_name = old_file_name + "[copy]"
new_file = open(new_file_name, "w")
'''Terminal
$ 複製檔案.py
請輸入欲複製的文件名(含檔名): hahaha.txt
$ ls
隨便寫寫.py 複製檔案.py hahaha.txt hahaha.txt[copy] xxxx.txt
'''
# hahaha.txt[copy] 這在win系統無法被正確執行!
```
`vi 複製檔案.py`
```python=5
# new_file = open("xxxx.txt", "w")
# new_file_name = old_file_name + "[copy]"
new_file_name = old_file_name.rreplace(".", "[copy].", 1)
new_file = open(new_file_name, "w")
'''Terminal
$ python3 0703_複製隨便寫寫.py
請輸入欲複製的文件名(含檔名): hahaha.txt
AttributeError: 'str' object has no attribute 'rreplace'
$ ipython3
In [xx] a = "xxx"
In [xx] a = r
replace() rjust() rstrip() rfind() rpartition() rindex() rsplit()
'''
```
`vi 複製檔案.py`
```python=5
# new_file = open("xxxx.txt", "w")
# new_file_name = old_file_name + "[copy]"
# new_file_name = old_file_name.rreplace(".", "[copy].", 1)
position = old_file_name.rfind(".")
new_file_name = old_file_name[:position] + "[copy]" + old_file_name[position:]
new_file = open(new_file_name, "w")
'''Terminal
$ 複製檔案.py
請輸入欲複製的文件名(含檔名): hahaha.txt
$ ls
隨便寫寫.py 複製檔案.py hahaha.txt hahaha.txt[copy] xxxx.txt hahaha[copy].txt
$ cat hahaha[copy].txt
哈哈哈
'''
```
```python
In [44]: f = open("hello_world.py")
In [45]: f.read()
Out[45]: '# -*- coding:utf-8 -*-\n\n# 輸出Hello,world\nprint("Hello, world")\n'
In [47]: f.close()
In [48]: f = open("hello_world.py")
In [49]: f.readlines()
Out[49]:
['# -*- coding:utf-8 -*-\n',
'\n',
'# 輸出Hello,world\n',
'print("Hello, world")\n']
In [51]: f.close()
In [52]: f= open("hello_world.py")
In [53]: f.readline()
Out[53]: '# -*- coding:utf-8 -*-\n'
In [54]: f.readline()
Out[54]: '\n'
In [55]: f.readline()
Out[55]: '# 輸出Hello,world\n'
In [56]: f.readline()
Out[56]: 'print("Hello, world")\n'
In [57]: f.readline()
Out[57]: ''
In [58]: f.readline()
Out[58]: ''
```
`vi 複製檔案.py`
```python=
old_file_name = input("請輸入欲複製的文件名(含檔名): ")
f_read = open(old_file_name, "r")
# new_file = open("xxxx.txt", "w")
# new_file_name = old_file_name + "[copy]"
# new_file_name = old_file_name.rreplace(".", "[copy].", 1)
position = old_file_name.rfind(".")
new_file_name = old_file_name[:position] + "[copy]" + old_file_name[position:]
new_file = open(new_file_name, "w")
# content = f_read.read() -> 萬一讀取的檔案超級大石，電腦就會掛掉
# new_file.write(content)
while True:
content = f_read.read(1024)
if len(content) == 0:
break
new_file.write(content)
f_read.close()
new_file.close()
```
```python
In [71]: f = open("0-100_even_numbers.py")
In [72]: cat 0-100_even_numbers.py
a = 1
while a<=100:
if a%2==0: # 如果a/2沒有餘數時
print(a)
a+=1
# read 會從頭開始讀
In [73]: f.read(1)
Out[73]: 'a'
In [74]: f.read(1)
Out[74]: ' '
In [75]: f.read(1)
Out[75]: '='
# tell 會告訴你現在讀到哪
In [78]: f.tell()
Out[78]: 3
# seek(cookie, whence=0, /) 可以指定位置
# Values for whence are:
# 0 -- start of stream
# 1 -- current stream position
# 2 -- end of stream
In [79]: f.seek(0,2)
Out[79]: 89
In [80]: f.read(1)
Out[80]: '' # 指針已經指到最後了，故後面沒東西了
In [82]: f.seek(0,0)
Out[82]: 0
In [73]: f.read(1)
Out[73]: 'a'
In [74]: f.read(1)
Out[74]: ' '
In [75]: f.read(1)
Out[75]: '='
In [78]: f.tell()
Out[78]: 3
In [88]: f.seek(50,0)
Out[88]: 50
In [89]: f.read(1)
Out[89]: '有'
```
Import os
---
```python
In [xx]: import os
# os.listdir = ls
In [116]: os.listdir
['xxxx.txt']
# os.rename = mv
In [118]: os.rename("xxxx.txt", "test.txt")
In [116]: os.listdir
['test.txt']
# os.remove = rm
In [120]: os.remove("test,txt")
In [116]: os.listdir
# os.mkdir = mkdir
In [122]: os.mkdir("哈哈")
In [116]: os.listdir
['哈哈']
# os.getcwd = pwd
In [124]: os.getcwd()
Out[124]: '/Users/xxxxx/Desktop/python'
# open 支援相對路徑與絕對路徑!
In [125]: f = open("../xxxx", "w")
In [134]: f = open("哈哈/xxxx", "w")
# os.chdir = cd
In [xx]: os.chdir("../")
In [124]: os.getcwd()
Out[124]: '/Users/xxxxx/Desktop'
In [116]: os.listdir
['xxxx']
In [xx]: os.chdir("python/哈哈")
In [124]: os.getcwd()
Out[124]: '/Users/xxxxx/Desktop/python/哈哈'
In [116]: os.listdir
['xxxx']
In [xx]: os.remove("xxxx")
In [xx]: os.chdir("../")
In [124]: os.getcwd()
Out[124]: '/Users/xxxxx/Desktop/python'
# os.rmdir = rmdir
In [150]: os.rmdir("哈哈/")
```
`vi 批量重命名.py`
```python=
import os
folder_name = input("請輸入重命名的文件夾：")
file_name = os.listdir(folder_name)
for name in file_name:
os.rename(name,"[小中夭]")
'''Terminal
$ python3 0704_批量重命名.py
請輸入重命名的文件夾：test
FileNotFoundError: [Errno 2] No such file or directory: '大中天-1.txt' -> '[小中夭]'
$ tree
.
├── test
│ ├── 大中天-1.txt
│ ├── 大中天-2.txt
│ ├── 大中天-3.txt
│ ├── 大中天-4.txt
│ └── 大中天-5.txt
└── 批量重命名.py
'''
# 當前路徑下找不到那些文件
# 方法一: 跳進去改
# 方法二: 指定路徑
```
`vi 批量重命名.py`
```python
import os
folder_name = input("請輸入重命名的文件夾：")
file_name = os.listdir(folder_name)
'''方法一
os.chdir(folder_name)
for name in file_name:
os.rename(name, "小中夭-" + name)
'''
'''方法二
for name in file_name:
os.rename("./" + folder_name + "/" + name, "./" + folder_name + "/" + "小中夭-" + name)
# os.rename(./test/大中天.txt, ./test/小中天-大中天.txt)
'''
# 方法二整理
for name in file_name:
old_file_name = "./" + folder_name + "/" + name
new_file_name = "./" + folder_name + "/" + "小中夭-" + name
os.rename(old_file_name, new_file_name)
```
Class
---
`vi class_basic.py`
```python
#class 類名:
# 屬性
# 方法
class Cat: # Class 名建議首字大寫
# 屬性
# 方法:
# def 定義在class裡面稱為方法
# class 中的方法參數要寫一個參數，用來傳遞當前的對象，常用self
def eat(self):
print("貓在吃飯")
def drink(self):
print("貓在喝水")
def introduce(self):
# print("%s 的年齡是%d"%(tom.name, tom.age))
print("%s 的年齡是%d"%(self.name, self.age))ff
# 創建一個對象
# 變量 = 執行class -> 執行class時，會在內存開啟一個空間(對象)並返回對象的引用(id)，接著用一個變量指向該引用
tom = Cat()
# 調用對象的方法
tom.eat()
tom.drink()
# 添加屬性
tom.name = "Tom"
tom.age = 100
# 輸出屬性方法一
# print("%s 的年齡是%d"%(tom.name, tom.age))
# 輸出屬性方法二
tom.introduce() # 相當於 tom.introduce(tom)
# 建立另一個對象
meowth = Cat()
meowth.name = "meowth"
meowth.age = 50
meowth.introduce()
'''Terminal
貓在吃飯
貓在喝水
Tom 的年齡是100
Tom 的年齡是100
# 問題出在introduce 的 print 不應取tom！
'''
```
`vi init.py`
```python
class Cat:
# 初始化對象
def __init__(self, new_name, new_age):
# print("------")
self.name = new_name
self.age = new_age
def eat(self):
print("貓在吃飯")
def drink(self):
print("貓在喝水")
def introduce(self):
print("%s 的年齡是%d"%(self.name, self.age))
tom = Cat("Tom", 100)
# tom.name = "Tom"
# tom.age = 100
tom.introduce()
meowth = Cat("Meowth")
# meowth.name = "meowth"
# meowth.age = 50
meowth.introduce()
'''Terminal
------
Tom 的年齡是100
------
meowth 的年齡是50
# 創建對象的流程
# ->等號右邊<-
# 1. 創建一個對象
# 2. python 會自動調用 __init__ -> 對象的引用會傳到__init__ -> self 指向該對象來執行 function
# ->等號左邊<-
# 3. 返回創建對象的引用給變數(tom/ meowth)
'''
```
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