python:pandas合并csv文件的方法(图书数据集成)

# -*- coding:utf-8 -*-
import csv as csv
import numpy as np
# -------------
# csv读取表格数据
# -------------
'''
csv_file_object = csv.reader(codecs.open('ReaderRentRecode.csv','rb'))
header = csv_file_object.next()
print header
print type(header)
print header[1]
data = []
for row in csv_file_object:
  data.append(row)
data = np.array(data)
print data[0::,0]
'''
# -------------
# pandas读取表格数据
# -------------
import pandas as pd
df = pd.read_csv('ReaderRentRecode.csv') # 读者借阅信息表
'''
print df.head()
print '----------------'
print df[['读者证号','读者姓名','书名','中图法分类号']] # 选取其中的四列
print '------------------------------------------------------------------'
print
'''
dd = pd.read_csv('ReaderInformation.csv')
'''
print dd.head()
print '----------------'
print dd[['读者证号','读者性别','读者单位','读者类别']]
print '------------------------------------------------------------------'
print
'''
data = pd.merge(df,dd,on=['读者证号','读者姓名'],how='left') # pandas csv表左连接
data = data[['读者证号','中图法分类号','读者类别']]
print data
print '------------------------------------------------------------------'
print
# -------------
# pandas写入表格数据
# -------------
data.to_csv(r'data.csv',encoding='gbk')