CODEWITHSUNDEEP
pythonpython-2.7
paolov
paolov

Reputation: 2347

How is replace done in python for quote backslash?

The following shows what I want to do:

>>> "input '\t' quote tab".replace("'\\",'replace')
"input '\t' quote tab"
>>>

The output shows that the quote and backslash are not replaced.

I wonder why.

Upvotes: 1

Views: 130

Answers (2)

MSeifert
MSeifert

Reputation: 152860

\t is one character (as pointed out by @MaLiN2223). If you want it to be "raw" then you need to use raw strings:

>>> r"input '\t' quote tab".replace("'\\", 'replace')
"input replacet' quote tab"

The following "escaped sequences" are treated as one-character unless an 'r' or 'R' string is used (taken from the python3 documentation and the python2 equivalent):

\newline    Ignored      
\\          Backslash (\)    
\'          Single quote (')     
\"          Double quote (")     
\a          ASCII Bell (BEL)     
\b          ASCII Backspace (BS)     
\f          ASCII Formfeed (FF)      
\n          ASCII Linefeed (LF)      
\N{name}    Character named name in the Unicode database (Unicode only)      
\r          ASCII Carriage Return (CR)   
\t          ASCII Horizontal Tab (TAB)   
\uxxxx      Character with 16-bit hex value xxxx (Unicode only)
\Uxxxxxxxx  Character with 32-bit hex value xxxxxxxx (Unicode only)
\v          ASCII Vertical Tab (VT)      
\ooo        Character with octal value ooo
\xhh        Character with hex value hh

Upvotes: 3

MaLiN2223
MaLiN2223

Reputation: 1298

I think this is because python desn't see this particual \ as \ but as part of \t. And since \t is single character, you cannot replace part of it.

Where as in this example: 

"input '\t' quote tab'\\".replace("'\\",'replace')

Output will be:

"input '\t' quote tabreplace"

Upvotes: 2

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