how to replace back slash character with empty string in python

The error is because you did not add a escape character to your '\', you should give \\ for backslash (\)

In [147]: foo = "a\c\d" # example string with backslashes

In [148]: foo 
Out[148]: 'a\\c\\d'

In [149]: foo.replace('\\', " ")
Out[149]: 'a c d'

In [150]: foo.replace('\\', "")
Out[150]: 'acd'

We need to specify that we want to replace a string that contains a single backslash. We cannot write that as "\", because the backslash is escaping the intended closing double-quote. We also cannot use a raw string literal for this: r"\" does not work.

Instead, we simply escape the backslash using another backslash:

result = string.replace("\\","")