正则表达式re 封装

import re

def replace(s, d):
    p = '\$\{(.*?)}'
    for v in d.values():
        print('v:', v)
        s = re.sub(p, v, s, count=1)   # 函数以列表返回字典中的所有值
    print('替换后的s：', s)

s = '{"mobilephone": "${borrow_user}", "pwd": "${borrow_pwd}"}'
d = {"mobilephone": "18511295864", "pwd": "123456"}
replace(s, d)                #替换后的s： {"mobilephone": "18511295864", "pwd": "123456"}

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第二种方式:

def replace(s, d):
    p = '\$\{(.*?)}'
    while re.search(p, s) is not None:
        m = re.search(p, s)
        key = m.group(1)
        value = d[key]
        s = re.sub(p, value, s, count=1)
    return s

s = '{"mobilephone": "${borrow_user}", "pwd": "${borrow_pwd}"}'
d = {'borrow_user': '18511295864', 'borrow_pwd': '123456'}
s=replace(s, d)
print(s)