用于字符串替换的python正则表达式

Question

我想替换包含以下单词"$%word $%"的字符串部分我想用字典的值替换它,相应的键等于word.

换句话说,如果我有一个字符串:"blahblahblah $%word $%blablablabla $%car $%"和一个字典{word:'wassup',car:'toyota'}

字符串将是"blahblahblah wassup blablablabla toyota"

你如何在python中实现它,我正在考虑使用字符串替换和正则表达式.

Answer 1

re.sub与函数一起使用作为repl参数:

import re

text =  "blahblahblah $%word$% blablablabla $%car$%"
words = dict(word="wassup", car="toyota")

def replacement(match):
    try:
        return words[match.group(1)]  # Lookup replacement string
    except KeyError:
        return match.group(0)  # Return pattern unchanged

pattern = re.compile(r'\$%(\w+)\$%')
result = pattern.sub(replacement, text)

如果要在使用时传递替换表re.sub,请使用functools.partial:

import functools

def replacement(table, match):
    try:
        return table[match.group(1)]
    except:
        return match.group(0)

table = dict(...)
result = pattern.sub(functools.partial(replacement, table), text)

......或实施的课程__call__:

class Replacement(object):
    def __init__(self, table):
        self.table = table
    def __call__(self, match):
        try:
            return self.table[match.group(1)]
        except:
            return match.group(0)

 result = pattern.sub(Replacement(table), text)