python - 数据框列的正则表达式

Question

我只想取出数据框列的日期部分，其中包含类似的数据

$83,00010/7/2016       10/7/2016  # is the date here
$721,0002/7/2015       2/7/2015  # is the date here
$3,00012/12/2015       12/12/2015  # is the date here

我尝试过类似的模式

^(?!,\d{3}) and (\$[,\d{3}]*\,\d{3}) 

但我无法准确选择日期部分。

Answer 1

这有点复杂，我们先从一个简单的表达式开始，然后再扩展它。我希望我们的资金部分中有 ,，然后我们可以尝试:

,\d{3}(\d{1,2}\/.+?\/\d{4})

DEMO

或

([1-3]?\d\/.+?\/\d{4})

DEMO

测试

# coding=utf8
# the above tag defines encoding for this document and is for Python 2.x compatibility

import re

regex = r"([1-3]?\d\/.+?\/\d{4})"

test_str = ("$83,00010/7/2016 ----> 10/7/2016 is the date here,\n"
    "$721,0002/7/2015 ----> 2/7/2015 is the date here,\n"
    "$3,00012/12/2015  -----> 12/12/2015 is the date here")

matches = re.finditer(regex, test_str, re.MULTILINE)

for matchNum, match in enumerate(matches, start=1):

    print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group()))

    for groupNum in range(0, len(match.groups())):
        groupNum = groupNum + 1

        print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum)))

# Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.

正则表达式电路

jex.im可视化正则表达式: