合并两个编码不同的文本

import chardet
gbktxt = './gbk编码.txt'
utf8txt = './utf8编码.txt'
def pcode():
    with open(gbktxt,'r',encoding='gbk') as g:
        infog = g.read()
    with open(utf8txt,'r',encoding='utf8') as u:
        infou = u.read()
    u = infog + infou
    z = input('请输入')
    with open(f'./{z}.txt','w',encoding='utf8') as ze:
        ze.write(u)
    j =  open(f'./{z}.txt','rb')  
    data = j.read()
    return chardet.detect(data)   #查看文件内的编码属性
print(pcode())