Python中CSV文件的读写库操作方法

csv.reader(csvfile, dialect='excel', **fmtparams)

import csv
with open('file.csv', 'r') as input_file:
    file_content = csv.reader(input_file, delemiter=',')
    for row in file_content:
        # code here
        pass

import csv
with open('file.csv', 'w', newline='') as output_file:
    file_writer = csv.writer(output_file, delimiter=',')
    file_writer.writerow(['Spam'] * 5 + ['Baked Beans'])
    file_writer.writerow(['Spam', 'Lovely Spam', 'Wonderful Spam'])

csv.DictReader(
    f,
    fieldnames=None,
    resTKEy=None, restval=None,
    dialect='excel',
    *args, **kwds
)

import csv
with open('file.csv') as input_file:
    reader = csv.DictReader(input_file)
    for row in reader:
        print(row['first_name'], row['last_name'])

# Eric Idle
# John Cleese

print(row)
# {'first_name': 'John', 'last_name': 'Cleese'}

csv.DictWriter(
    f,
    fieldnames,
    restval='', extrasaction='raise',
    dialect='excel',
    *args, **kwds
)

import csv

with open('names.csv', 'w', newline='') as output_file:
    fieldnames = ['first_name', 'last_name']
    writer = csv.DictWriter(output_file, fieldnames=fieldnames)
    # 将
    writer.writeheader()
    writer.writerow({'first_name': 'Baked', 'last_name': 'Beans'})
    writer.writerow({'first_name': 'Lovely', 'last_name': 'Spam'})
    writer.writerow({'first_name': 'Wonderful', 'last_name': 'Spam'})

csv.reGISter_dialect(
    'unixpwd',
    delimiter=',',
    quoting=csv.QUOTE_MINIMAL,
    quotechar='"',
    doublequote=True,
    escapechar=None,
    lineterminator='\r\n',
    skipinitialspace=False,
    strict=False
)

import csv
csv.register_dialect(
    'unixpwd',
    delimiter=':',
    quoting=csv.QUOTE_NONE,
    ...
)
with open('passwd', newline='') as f:
    reader = csv.reader(f, 'unixpwd')

with open('example.csv', newline='') as csvfile:
    # 通过文件的前1024行来确定文件的格式规范
    dialect = csv.Sniffer().sniff(csvfile.read(1024))
    # 将指针重置，从文件开始进行读取
    csvfile.seek(0)
    reader = csv.reader(csvfile, dialect)
    # ... process CSV file contents here ..