当字段包含逗号时在逗号上分割字符串

Question

考虑以下字符串：

'538.48,0.29,"533.59 - 540.00","AZO",102482,"+0.05%","N/A",0.00,535.09,"AutoZone, Inc. Co",538.77,"N/A"'

我需要将其拆分为一个列表，如下所示：

[538.48, 0.29, "533.59 - 540.00", "AZO", 102482, "+0.05%" , "N/A", 0.00, 535.09, "AutoZone, Inc. Co", 538.77, "N/A"]

问题是我不能使用list.split(',')因为第10个字段中包含逗号。 问题是，当任意字段可能带有逗号时，如何最好地将原始字符串拆分为列表？

Answer 1

使用csv模块而不是尝试自己拆分它，它可以立即处理带引号的值，包括包含定界符的带引号的值：

>>> import csv
>>> from pprint import pprint
>>> data = '538.48,0.29,"533.59 - 540.00","AZO",102482,"+0.05%","N/A",0.00,535.09,"AutoZone, Inc. Co",538.77,"N/A"'
>>> reader = csv.reader(data.splitlines())
>>> pprint(next(reader))
['538.48',
 '0.29',
 '533.59 - 540.00',
 'AZO',
 '102482',
 '+0.05%',
 'N/A',
 '0.00',
 '535.09',
 'AutoZone, Inc. Co',
 '538.77',
 'N/A']

注意'AutoZone, Inc. Co'列的值。

如果要从文件读取此数据，请直接将文件对象传递给csv.reader()对象，而不是将其传递给字符串序列。

通过设置quoting=csv.QUOTE_NONNUMERIC ，您甚至可以将数字值（任何未引用的值）解释为浮点值：

>>> reader = csv.reader(data.splitlines(), quoting=csv.QUOTE_NONNUMERIC)
>>> pprint(next(reader))
[538.48,
 0.29,
 '533.59 - 540.00',
 'AZO',
 102482.0,
 '+0.05%',
 'N/A',
 0.0,
 535.09,
 'AutoZone, Inc. Co',
 538.77,
 'N/A']