如何在Python中使用双重反斜杠替换单个字符串

Question

I want to replace double backslashes to single one for byte string in Python.

For example, there is a bytes string.

word = b'Z\xa6\x97\x86j2\x08q\\r\xca\xe6m'

I need this bytes string.

word = b'Z\xa6\x97\x86j2\x08q\r\xca\xe6m'

If I use replace like:

word = word.replace(b"\\",b"\")

I got this error.

File "test.py", line 79
word = word.replace(b"\\", b"\")
                               ^
SyntaxError: EOL while scanning string literal

Does anyone know how to do it?

Answer 1

\\\\ is not double backslash but one escaped. Look:

print b'Z\xa6\x97\x86j2\x08q\\r\xca\xe6m'
# Z���jq\r��m

And \\r (from your desired output) is not 2 chars but one:

print b'Z\xa6\x97\x86j2\x08q\r\xca\xe6m'
# ��m�jq

(When printing it to terminal, carriage return \\r prevents us from seen the first letter Z )

If you really want to replace '\\\\r' with '\\r' , you can do:

print repr(word.replace('\\r', '\r'))
# 'Z\xa6\x97\x86j2\x08q\r\xca\xe6m'
print word.replace('\\r', '\r')
# ��m�jq

Or, if you want to replace all the escape sequences . Python2 version:

print repr(b'1\\t2\\n3'.decode('string_escape'))
# '1\t2\n3'
print b'1\\t2\\n3'.decode('string_escape')
# 1 2
# 3

Python3 version:

print(repr(b'1\\t2\\n3'.decode('unicode_escape')))
# '1\t2\n3'
print(b'1\\t2\\n3'.decode('unicode_escape'))
# 1 2
# 3

Answer 2

your \\r is a carriage return character. So \\\\r is \\ plus carriage return. You won't find \\\\ in your string.

What "works" is to replace backslash+CR by just CR:

word = b'Z\xa6\x97\x86j2\x08q\\r\xca\xe6m'

print(word.replace(b"\\r",b"\r"))

result:

b'Z\xa6\x97\x86j2\x08q\r\xca\xe6m'

but I'm not sure that's what you meant from the start (that is: inserting a carriage return char in your bytes string)

Answer 3

You have a byte stream. You need to escape '\\' and decode bytes.

word = b'Z\xa6\x97\x86j2\x08q\\r\xca\xe6m'
new_word = (str(word).encode('utf-8'))
print(new_word.replace(b"\\\\",b"\\").decode('ascii'))