TypeError：write（）参数必须是str而不是byte，升级到python 3

Question

我正在尝试将代码升级到python3。这行遇到了一些麻烦，

output_file = open(working_dir + "E"+str(s)+".txt", "w+")

output_file.write(','.join(headers) + "\n")

并得到这个错误 TypeError: sequence item 0: expected str instance, bytes found

我尝试过的

  output_file.write(b",".join(headers) + b"\n")

TypeError: write() argument must be str, not bytes

香港专业教育学院也尝试decode()在联接上使用，也尝试使用r和w+b打开。

如何str在python 3中转换为？

Answer 1

EDIT: to read on how to convert bytes to string, follow the link provided by Martijn Pieters in the 'duplicate' tag.

my original suggestion

output_file.write(','.join([str(v) for v in values]) + "\n")

would give for example

values = [b'a', b'b', b'c']
print(','.join([str(v) for v in values]))
# b'a',b'b',b'c'

So despite this works, it might not be desired. If the bytes should be decoded instead, use bytes.decode() (ideally also with the appropriate encoding provided, for example bytes.decode('latin-1'))

values = [b'a', b'b', b'c']
print(','.join([v.decode() for v in values]))
# a,b,c