Just use all \(backslash) the other way(/),the no octal value or other escape characters problems.
>>> s = '\4.1' >>> s '\x04.1' >>> print(s) .1 >>> # Fix >>> s = '/4.1' >>> s '/4.1' >>> print(s) /4.1 >>> s = 'C:/Program Files (x86)/Citrix/ICA Client/4.1/wfcrun32.exe' >>> print(s) C:/Program Files (x86)/Citrix/ICA Client/4.1/wfcrun32.exe