value_counts()是一種查看表格某列中有多少個(gè)不同值的快捷方法，并計(jì)算每個(gè)不同值有在該列中有多少重復(fù)值。
value_counts()是Series擁有的方法，一般在DataFrame中使用時(shí)，需要指定對(duì)哪一列或行使用

import pandas as pd
import numpy as np
filepath='C:\python\data_src\GFSCOFOG_03-05-2018 03-04-36-54_timeSeries\GFSCOFOG_CHA.csv'
data = pd.read_csv(filepath,encoding='utf-8')

數(shù)據(jù)樣例如下圖所示

數(shù)據(jù)樣例

查看Unit Name中有哪些不同的值，并計(jì)算每個(gè)值有多少個(gè)重復(fù)值

data['Unit Name'].value_counts()

data['Unit Name'].value_counts()
#輸出
Percent of GDP                  3561
Domestic currency               3561
Percent of total expenditure     470
Name: Unit Name, dtype: int64

查看Sector Name中有哪些不同的值，并計(jì)算每個(gè)值有多少個(gè)重復(fù)值

data['Sector Name'].value_counts()

data['Sector Name'].value_counts()
#輸出結(jié)果
Extrabudgetary central government                   1020
Social security funds                               1002
Central government (incl. social security funds)     944
Budgetary central government                         944
Local governments                                    944
General government                                   944
Central government (excl. social security funds)     944
State governments                                    850
Name: Sector Name, dtype: int64