Python 正则表达式以特殊格式的字符串命名组

Question

目标：

1. 我有输入字符串，它由逗号和键值分隔
2. 我想用名称组编写正则表达式，以便提取和替换每个属性的值

在字符串*keyword , property1 = ABC, property2 = 2 中，我想按名称查找和替换property1 和property2 的值

对于给定的字符串 *keyword , property1 = ABC, property2 = 2 ，结果字符串应该是 *keyword , property1 = DEF, property2 = 10

见下方代码

import re

# find property1 in given string and replace its new value
property1 = 'DEF'
# find property2 in given string and replace its new value
property2 = '10'

line1 = '*keyword , property1 = ABC,  property2 = 2 '
line2 = '*keyword , property2 = 2,  property1 = ABC ' #property2 comes before proeprty1
line3 = '*keyword,property1=ABC,property2= 2' #same as line 1 but without spaces

regex_with_named_group = r'=\s*(.*)\s*,\s*property1=\s*(.*)\s*,'

line1_found = re.search(regex_with_named_group, line1)
line2_found = re.search(regex_with_named_group, line2)
line3_found = re.search(regex_with_named_group, line3)

if line1_found:
    print( line1_found.group('property1'), line1_found.group('property2') )

if line2_found:
    print( line2_found.group('property1'), line2_found.group('property2') )

if line3_found:
    print(line3_found.group('property1'), line3_found.group('property2'))

Answer 1

为了实现你的目标，我建议考虑使用re.sub 函数。

import re

line0 = '*keyword , fruit=apple, juice= mango'
line1 = '*keyword , property1 = ABC,  property2 = 2 '
line2 = '*keyword , property2 = 2,  property1 = ABC ' #property2 comes before proeprty1
line3 = '*keyword,property1=ABC,property2= 2' #same as line 1 but without spaces

regex_with_named_group = re.compile(r'(?P<prop>\w+)(?P<map>\s*=\s*)(?P<val>\w+)')
repl = {'fruit':'avocado', 'property1':170}
for l in [line0, line1, line2, line3]:
    s = regex_with_named_group.sub(lambda m: m.group('prop') + m.group('map') +
                                             (str(repl[m.group('prop')])
                                              if m.group('prop') in repl
                                              else m.group('val')), l)
    print(s)

结果：

*keyword , fruit=avocado, juice= mango
*keyword , property1 = 170,  property2 = 2 
*keyword , property2 = 2,  property1 = 170 
*keyword,property1=170,property2= 2

Demo.