Xiang Wang @ 2017-04-21 10:48:07

official reference

Module Contents

Dialects and Formatting Parameters

class MyDialect(Dialect):
    """示例自定义格式"""
    delimiter = ";"
    quotechar = "%"
    quoting = QUOTE_ALL
    lineterminator = "end\r\n"

csv.DictReader

file = open('filename.csv')
reader = csv.DictReader(file)
reader.fieldnames
>>> ['number', 'name', 'tel']
for row in reader:
    print(row) >>> {'tel': '', 'name': 'company', 'number': 'No. 1'}

dictwriter 

example

import csv
with open('names.csv', 'w') as csvfile:  # 也可以用a模式，继续写入。但是要注意fieldnames需要务必顺序正确
    fieldnames = ['first_name', 'last_name']
    writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
    writer.writeheader()
    writer.writerow(<dict>)
    writer.writerows([<dict1>, <dict2>])

csv.DictWriter
- extrasaction = 'raise' | 'ignore' raise ValueError or not if there is another keys in <dict> data
- delimiter=',' the delimiter between columns
Attention
- If a key is missing in the dict, the data will set blank instead of raise exception