import re

def choose_stack_code(num_code):
    num_code = num_code[0:6]
    sh_code = ['6', '900']
    sz_code = ['0', '3', '200', '300']
    for itm in sh_code:
        if re.match(itm, num_code) != None:
            return 'sh.' + num_code
    for itm in sz_code:
        if re.match(itm, num_code) != None:
            return 'sz.' + num_code
    return ''

with open("股票代码大全.txt",'r',encoding="utf-8") as f:
    code_list = re.findall('[0-9]{6}',f.read())

ret_list = []
for code in code_list:
    ret = choose_stack_code(code)
    if ret:
        ret_list.append(ret)
code_string = '\n'.join(ret_list)
with open("股票代码.txt",'w') as f:
    f.write(code_string)