04.计算、排序与筛选

计算与排序

 1 import pandas as pd
 2 
 3 books = pd.read_excel(\'Books2.xlsx\')
 4 print(books.head(3))
 5 
 6 books[\'Price\']=books[\'ListPrice\'] * books[\'Discount\']
 7 print(books)
 8 
 9 for i in books.index:
10     books[\'Price\'].at[i] = books[\'ListPrice\'].at[i] * books[\'Discount\'].at[i]
11 print (books)
12 books.set_index(\'ID\', inplace=True)
13 books.to_excel(\'Books21.xlsx\')
14 print(\'Done!\')
15 
16 books = pd.read_excel(\'Books2.xlsx\')
17 for i in books.index:
18     books[\'Price\'].at[i] = books[\'ListPrice\'].at[i] * books[\'Discount\'].at[i]
19 print (books)
20 books.set_index(\'ID\', inplace=True)
21 # books.to_excel(\'Books22.xlsx\')
22 # print(\'Done!\')

排序

 1 # 排序
 2 import pandas as pd
 3 
 4 products = pd.read_excel(\'007/List.xlsx\', index_col=\'ID\')
 5 # ascending 为 倒置排序
 6 products.sort_values(by=\'Price\', inplace=True, ascending=False)
 7 print(products)
 8 
 9 # 排序
10 import pandas as pd
11 
12 products = pd.read_excel(\'007/List.xlsx\', index_col=\'ID\')
13 products.sort_values(by=[\'Worthy\', \'Price\'], ascending=[True, False], inplace=True)
14 print(products)

数据筛选

 1 # 数据筛选
 2 import pandas as pd
 3 
 4 def age_18_to_30(a):
 5     # returen a >=18 and a< 30 和下相同，下面为python特有
 6     return 18<= a <30
 7 
 8 def level_a(s):
 9     return 85 <= s <= 100
10 
11 students = pd.read_excel(\'008/Students.xlsx\', index_col=\'ID\')
12 # loc为 location定位的缩写
13 # students = students.loc[students[\'Age\'].apply(age_18_to_30)].loc[students[\'Score\'].apply(level_a)]
14 # students = students.loc[students.Age.apply(age_18_to_30)].loc[students.Score.apply(level_a)]
15 students = students.loc[students.Age.apply(lambda a:18<= a <30)] \
16 .loc[students.Score.apply(lambda s:85 <= s <= 100)]
17 # 上述三种方法一样 空格+\ 可以换行不影响代码运行
18 print(students)