第五堂 python四大基本型態、結構

List 陣列、串列

list是有序的

string = "String"

for s in string:
    print(s)

# "String" => "S","t","r","i","n","g"

Tuple 元組

tuple是有序的

跟list很像，但差別在於 初始值不能改變

初始化方法 Tuple

t1 = tuple()
t2 = ()

print(t1)
print(t2)

初始值給了之後不能再修改

t = (1,2,3)

t[0] = 5

Dict 字典

一個對應一個，Key對應到Value
像字典一樣，一個名詞對應到一個解釋

d = {
    "a":"abc",
    "b":"bcd"
    }

print(d)
print(d['a'])
print(d['b'])

要用到的東西一定要在字典內，否則會產生KeyError錯誤

d = {
    "a":"abc",
    "b":"bcd",
    "ab":"1231213",
    5: "這是五"
    }

print(d)
print(d['ab'])
print(d['a'])
print(d['b'])
print(d[5])

# 只會印出完全一樣的key(鍵)的值，
# 會找完全一樣的Key來做對應
# dict的key中可以同時有數字、字串

dict是無序的，沒有前後順序

d = {
    "cat":"小貓",
    "dog":"小狗",
    "bird":"小鳥",
    "fish":"魚",
    }

print(d['cat'])

for i in d:
    print("key:", i, " value:", d[i])

Set 集合

set是無序的

Set跟Dict都是用大括號{}，
特點在於，會把重複的東西自動去除

s = set()
s = {1,2,3,1,2,3,"1","2","3"}

print(s)

去除重複的資料

l = ["小明","小華","小東","小明"]

print(l)

print(set(l)) # 把list轉成set