# 0411
https://www.learncodewithmike.com/2020/11/python-pandas-dataframe-tutorial.html

### 上課筆記

容器：串列 字典 panda


# 手工掛載雲端硬碟
# 寫入CSV  #'/路徑///資料夾/檔名.副檔名(txt)', 'w(寫入)' 
with open('/content/drive/MyDrive/___DataSet/001_Hello.txt', 'w') as f:#以打開檔案為基礎 並把檔案命名為f
  f.write('Hello Google Drive 溫瑩瑄')  #把()寫入f檔案

# 讀取CSV
with open('/content/drive/MyDrive/___DataSet/001_Hello.txt', 'r') as f:  
  ss=f.read() #r(讀取)
  print(ss)

Hello Google Drive 溫瑩瑄

# 刪除檔案
import os
if os.path.exists("/content/drive/MyDrive/___DataSet//001_Hello.txt"): #檢查路徑是否存在
  os.remove("/content/drive/MyDrive/___DataSet//001_Hello.txt") #移除檔案
  print("檔案已經刪除") #如果刪除就印出字串('檔案已經刪除')
else:
  print("檔案不存在") #如果上面的if不成立就跑else如果上面的if不成立就跑else
  
檔案已經刪除

#讀取雲端硬碟中的excel檔
import pandas as pd #pd命名
df = pd.read_excel('/content/drive/My Drive/___DataSet/001_Income_F.xlsx')
df


#讀取雲端硬碟中的excel檔
import pandas as pd 
data = pd.read_excel("/content/drive/My Drive/___DataSet/110 學年度全國大專校院及校長名錄(含學校本部地址).xlsx")
data

159 rows × 14 columns


import pandas as pd 
data = pd.read_excel("/content/drive/My Drive/___DataSet/程設0411.xlsx")
data


import pandas as pd
 
 
grades = {
    "name": ["Mike", "Sherry", "Cindy", "John"],
    "math": [80, 75, 93, 86],
    "chinese": [63, 90, 85, 70]
}
 
df = pd.DataFrame(grades)
 
print("使用字典來建立df：")
print(df)
df


grades = [
    ["Mike", 80, 63],
    ["Sherry", 75, 90],
    ["Cindy", 93, 85],
    ["John", 86, 70]
]
 
new_df = pd.DataFrame(grades)
print("使用陣列來建立df：")
print(new_df)


import pandas as pd
 
 
grades = {
    "name": ["Mike", "Sherry", "Cindy", "John"],
    "math": [80, 75, 93, 86],
    "chinese": [63, 90, 85, 70]
}
 
df = pd.DataFrame(grades)
df.index = ["s1", "s2", "s3", "s4"]  #自訂索引值
df.columns = ["student_name", "math_score", "chinese_score"]  #自訂欄位名稱
print(df)
df


head()：取得最前面的n筆資料，並且會回傳一個新的Pandas

import pandas as pd
 
 
grades = {
    "name": ["Mike", "Sherry", "Cindy", "John"],
    "math": [80, 75, 93, 86],
    "chinese": [63, 90, 85, 70]
}
 
df = pd.DataFrame(grades)
print("原來的df")
print(df)

print("=================================")
 
new_df = df.head(2)

print("取得最前面的兩筆資料")

print(new_df)

print("=================================")
print("取得單一欄位資料(型別為DataFrame)")
print(df[["name"]])
print("=================================")
print("取得多欄位資料(型別為DataFrame)")
print(df[["name", "chinese"]]) #[[串列]]
print("=================================")
 
print("取得索引值0~2的資料")
print(df[0:3])
print("=================================")
 
print("利用at()方法取得索引值為1的math欄位資料")
print(df.at[1, "math"])
print("=================================")
 
print("利用iat()方法取得索引值為1的第一個欄位資料")
print(df.iat[1, 2]) #先切列在切欄
print("=================================")
 
print("取得資料索引值為1和3的name及chinese欄位資料集")
print(df.loc[[1, 3], ["name", "chinese"]])
print("=================================")

print("取得資料索引值為1和3的第一個及第三個欄位資料集")
print(df.iloc[[1, 3], [0, 2]]) #1.sherry2.john列,0name 2chhinese欄 


import pandas as pd
 
 
grades = {
    "編號": ["A001", "A002", "A003", "A004","A005"],
    "體重": [60, 50, 80, 75, 72],
    "身高": [165, 157, 182, 175, 170]
}

df = pd.DataFrame(grades)
df


for i in range(0,5):
  for j in range(0,5):
   print(f'(i),(j)')
   print("=============")
   print(df.at[i, "編號"])
 
(i),(j)
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A001
(i),(j)
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A001
(i),(j)
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A001
(i),(j)
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A001
(i),(j)
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A001
(i),(j)
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A002
(i),(j)
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A002
(i),(j)
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A002
(i),(j)
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A002
(i),(j)
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A002
(i),(j)
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A003
(i),(j)
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A003
(i),(j)
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A003
(i),(j)
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A003
(i),(j)
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A003
(i),(j)
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A004
(i),(j)
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A004
(i),(j)
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A004
(i),(j)
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A004
(i),(j)
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A004
(i),(j)
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A005
(i),(j)
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A005
(i),(j)
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A005
(i),(j)
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A005
(i),(j)
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A005