can not change double to single dash

[oco]

python 2.7.11

def leftrotate(l, n):
    return l[n:] + l[:n]

def rightrotate(l, n):
    return l[-n:] + l[:-n]

def encode(s, k, kk):
    l = [ord(i) for i in s]
    return leftrotate(''.join([chr(i + k) for i in l]), kk)

def decode(s, k, kk):
    l = [ord(i) for i in rightrotate(s.replace("\\\\","\\"), kk)]
    return ''.join([chr(i - k) for i in l])

>>> "\\".replace("\\\\","\\")
'\\'
>>> encode("xxxxxxQ\|2",3,7)
'_\x7f5{{{{{{T'
>>>
>>> decode("_\x7f5{{{{{{T",3,7)
'xxxxxxQ\\|2'

decode error,

then i try to patch with

decode("_\x7f5{{{{{{T",3,7).replace("\\\\","\\")

but can not change double to single

>>> "\\".replace("\\\\","\\")
'\\'

[killerrex]

Please put your code in the [python][/python] markers or all the indentation is lost...

Notice that your statement (the syntax highlighting does not like your profuse use of the backslash...)

>>> "\\".replace("\\\\","\\")
'\\'

is equivalent to:

>>> "A".replace("AA", "A")
'A'

And there is obvious that in a string of 1 char there will be 0 replacements of a 2 chars group.
Your expression works when the input has 2 or more backslashes:

>>> bs = '\\'
>>> s = bs * 8
>>> s
'\\\\\\\\\\\\\\\\'
>>> len(s)
8
>>> s.replace("\\\\", "\\")
'\\\\\\\\'
>>> len(_)
4

[oco]

how to make two dash to one dash

[wavic]

In Python '\\' is a way to represent a single '\'. Since the backslash is an escape character to get a single '\' you have to escape it.

>>> print('\\')
\
>>> s = '\nGSG'
>>> print(s)

GSG
>>> s = '\\nGSG'
>>> print(s)
\nGSG

[oco]

"\\".replace("\\\\","\\")

but in variable it still is \\
how to replace to become \

i have google to get the print standard output result into variable, but variable show it still is \\

[wavic]

Yes in the variable you see it as '\\' but it is '\' when you print it. Just like the new line character. It has no graphical representation as the letters for example so we use '\n' to deal with it. And because the single backslash is an escape character we have to escape it with another one. So:

s = '\\no \\new line here'
print(s)

Output:
\no \new line here

But see this:

print(len(s))

Output:
18

If you count the characters in the string you will get 20 but as you can see the output they are 18. '\\' is a representation of '\'. For our convenience.

[oco]

i am not using print , i am used it as a password to do parameter in netmiko

how to replace \\ to \?

[wavic]

Print function prints what it is in the string. If there is double \\ in a Python string it's actually \.
Count the characters you see then use len(password) to see do you have single backslash or double.
Or can use raw strings.

This will show you that you have \ when you see \\ in a Python string.

>>> from hashlib import sha1
>>> sha1(bytes(r'my\password'.encode('utf-8'))).hexdigest()
'05d0aaf554af6c33a5b558f3d78345b422198522'
>>> sha1(bytes('my\\password'.encode('utf-8'))).hexdigest()
'05d0aaf554af6c33a5b558f3d78345b422198522'
>>> 

So do you have single \ when you see \\ in the string? I think so.