Question

我具有以下示例内容的csv文件，我只需要将列表部分存储为csv格式。

file.csv：

Row 1: [123, abc, aa-dd daw, 122, 2011-11-11 00:00:00, None, None, None, GA GH, 1.9912109375]
Row 2: [234, bcd, bc-dd acs, 332, 2012-11-11 00:00:00, None, addad, None, GB GG, 1.22]
Row 3: [345, cda, cd-dd adc, 12312, 2013-11-11 00:00:00, None, None, dsa, GV GA, 1.925262]

代码：

import re

file=open('file.csv')
file_contents=file.read()
regx = re.compile(r'\[(.*)\]')
column_fetch=regx.findall(file_contents)
print column_fetch

预期输出（file.csv）：

123, abc, aa-dd daw, 122, 2011-11-11 00:00:00, None, None, None, GA GH, 1.9912109375
234, bcd, bc-dd acs, 332, 2012-11-11 00:00:00, None, addad, None, GB GG, 1.22
345, cda, cd-dd adc, 12312, 2013-11-11 00:00:00, None, None, dsa, GV GA, 1.925262

实际输出：

[123, abc, aa-dd daw, 122, 2011-11-11 00:00:00, None, None, None, GA GH, 1.9912109375 234, bcd, bc-dd acs, 332, 2012-11-11 00:00:00, None, addad, None, GB GG, 1.22 345, cda, cd-dd adc, 12312, 2013-11-11 00:00:00, None, None, dsa, GV GA, 1.925262]

Answer 1

import csv

with open("data.csv", 'r')as infile:
    reader = csv.reader(infile)
    for row in reader:
        row = ' '.join(row)
        print(row[7:].strip("[]"))

输出：

Perform simple and compound queries in Cloud Firestore

Answer 2

尝试这种方式，将行作为列表，然后您可以做任何想做的事情：

import re

file=open('test-001.csv')
file_contents=file.readlines()
regx = re.compile(r'\[(.*)\]')
for line in file_contents:
  line_fetch=regx.findall(line)
  print (line_fetch)
  # print (line_fetch.__class__)  # uncomment to see

Answer 3

问题是由您的正则表达式r'\[(.*)\]'引起的，因为*是贪婪的搜索，因此它正在寻找最长的匹配项，因此您会从第一个[开始到最后一个结束]，为避免这种情况，请使用*?表示非贪婪搜索，例如：

data = '''Row 1: [123, abc, aa-dd daw, 122, 2011-11-11 00:00:00, None, None, None, GA GH, 1.9912109375]
Row 2: [234, bcd, bc-dd acs, 332, 2012-11-11 00:00:00, None, addad, None, GB GG, 1.22]
Row 3: [345, cda, cd-dd adc, 12312, 2013-11-11 00:00:00, None, None, dsa, GV GA, 1.925262]'''
rows = [i[1] for i in re.findall(r'(\[)(.*?)(\])',data)]
print(rows)

输出：

['123, abc, aa-dd daw, 122, 2011-11-11 00:00:00, None, None, None, GA GH, 1.9912109375', '234, bcd, bc-dd acs, 332, 2012-11-11 00:00:00, None, addad, None, GB GG, 1.22', '345, cda, cd-dd adc, 12312, 2013-11-11 00:00:00, None, None, dsa, GV GA, 1.925262']

例如，为了清楚起见，我省略了对文件部分的读写操作，而是直接将字符串分配给data。请注意，我使用正则表达式分组创建了三个组：

[

获取实际数据

]

然后提取中间一个。

Answer 4

作为熟悉熊猫的人，我会做这样的事情：

import pandas as pd
pd.read_csv('file.csv')
pd.to_csv('file_out.csv')

但是我不确定那正是您想要的。至少当您将csv作为pd.DataFrame时，您有很多选择。

从CSV文件中提取列表数据

4 个答案: