dic = {2:'bob',3:'alice'}
 output = open('/Users/Air/itchat/push.txt','wb')
 for i in dic:
    print (i,dic[i])
    write_str = str(i) + ' ' + str(dic[i]) + '\n'
    print(type(write_str))
    output.write(write_str)
output.close()

PyCharm运行报错如下：

2 bob
<class 'str'>

Traceback (most recent call last):
File "/Users/Air/itchat/test.py", line 8, in <module>

output.write(write_str)

TypeError: a bytes-like object is required, not 'str'

Process finished with exit code 1