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Python printing backslash without using it

I have the following issue. I need to represent '\' in Python without using '\'. Is there a way to achieve this using the functions print(), eval(), str() or repr()?

A first resource is chr, e.g., chr(92).
If chr does not fit your needs, you would get the backslash from "somewhere".
Under Windows, a possible "safe" place to look for is in path names.
E.g.,
import os
print( str(os.getcwd())[2] ) # (Almost certainly) gives you a backslash
print( os.sep ) # Gives you a backslash
Or, you may have it stored somewhere you know, and go look for it.
E.g., in a file, written in memory, etc.
I am not sure these are acceptable options for you.

You may do this with eval. As eval simply takes a string as an argument, you're arguably not using the chr built-in function directly ;)
Take this as an example and do not wonder about the double backslash, it's because a single one is for escaping characters:
>>> backslash = eval('chr(92)')
>>> backslash
'\\'
>>> len(backslash)
1
>>> print(eval('chr(92)'))
\
>>>

Print raw string from variable? (not getting the answers)

I'm trying to find a way to print a string in raw form from a variable. For instance, if I add an environment variable to Windows for a path, which might look like 'C:\\Windows\Users\alexb\', I know I can do:
print(r'C:\\Windows\Users\alexb\')
But I cant put an r in front of a variable.... for instance:
test = 'C:\\Windows\Users\alexb\'
print(rtest)
Clearly would just try to print rtest.
I also know there's
test = 'C:\\Windows\Users\alexb\'
print(repr(test))
But this returns 'C:\\Windows\\Users\x07lexb'
as does
test = 'C:\\Windows\Users\alexb\'
print(test.encode('string-escape'))
So I'm wondering if there's any elegant way to make a variable holding that path print RAW, still using test? It would be nice if it was just
print(raw(test))
But its not

I had a similar problem and stumbled upon this question, and know thanks to Nick Olson-Harris' answer that the solution lies with changing the string.
Two ways of solving it:
Get the path you want using native python functions, e.g.:
test = os.getcwd() # In case the path in question is your current directory
print(repr(test))
This makes it platform independent and it now works with .encode. If this is an option for you, it's the more elegant solution.
If your string is not a path, define it in a way compatible with python strings, in this case by escaping your backslashes:
test = 'C:\\Windows\\Users\\alexb\\'
print(repr(test))

In general, to make a raw string out of a string variable, I use this:
string = "C:\\Windows\Users\alexb"
raw_string = r"{}".format(string)
output:
'C:\\\\Windows\\Users\\alexb'

You can't turn an existing string "raw". The r prefix on literals is understood by the parser; it tells it to ignore escape sequences in the string. However, once a string literal has been parsed, there's no difference between a raw string and a "regular" one. If you have a string that contains a newline, for instance, there's no way to tell at runtime whether that newline came from the escape sequence \n, from a literal newline in a triple-quoted string (perhaps even a raw one!), from calling chr(10), by reading it from a file, or whatever else you might be able to come up with. The actual string object constructed from any of those methods looks the same.

I know i'm too late for the answer but for people reading this I found a much easier way for doing it
myVariable = 'This string is supposed to be raw \'
print(r'%s' %myVariable)

try this. Based on what type of output you want. sometime you may not need single quote around printed string.
test = "qweqwe\n1212as\t121\\2asas"
print(repr(test)) # output: 'qweqwe\n1212as\t121\\2asas'
print( repr(test).strip("'")) # output: qweqwe\n1212as\t121\\2asas

Get rid of the escape characters before storing or manipulating the raw string:
You could change any backslashes of the path '\' to forward slashes '/' before storing them in a variable. The forward slashes don't need to be escaped:
>>> mypath = os.getcwd().replace('\\','/')
>>> os.path.exists(mypath)
True
>>>

Just simply use r'string'. Hope this will help you as I see you haven't got your expected answer yet:
test = 'C:\\Windows\Users\alexb\'
rawtest = r'%s' %test

I have my variable assigned to big complex pattern string for using with re module and it is concatenated with few other strings and in the end I want to print it then copy and check on regex101.com.
But when I print it in the interactive mode I get double slash - '\\w'
as #Jimmynoarms said:
The Solution for python 3x:
print(r'%s' % your_variable_pattern_str)

Your particular string won't work as typed because of the escape characters at the end \", won't allow it to close on the quotation.
Maybe I'm just wrong on that one because I'm still very new to python so if so please correct me but, changing it slightly to adjust for that, the repr() function will do the job of reproducing any string stored in a variable as a raw string.
You can do it two ways:
>>>print("C:\\Windows\Users\alexb\\")
C:\Windows\Users\alexb\
>>>print(r"C:\\Windows\Users\alexb\\")
C:\\Windows\Users\alexb\\
Store it in a variable:
test = "C:\\Windows\Users\alexb\\"
Use repr():
>>>print(repr(test))
'C:\\Windows\Users\alexb\\'
or string replacement with %r
print("%r" %test)
'C:\\Windows\Users\alexb\\'
The string will be reproduced with single quotes though so you would need to strip those off afterwards.

To turn a variable to raw str, just use
rf"{var}"
r is raw and f is f-str; put them together and boom it works.

Replace back-slash with forward-slash using one of the below:
re.sub(r"\", "/", x)
re.sub(r"\", "/", x)

This does the trick
>>> repr(string)[1:-1]
Here is the proof
>>> repr("\n")[1:-1] == r"\n"
True
And it can be easily extrapolated into a function if need be
>>> raw = lambda string: repr(string)[1:-1]
>>> raw("\n")
'\\n'

i wrote a small function.. but works for me
def conv(strng):
k=strng
k=k.replace('\a','\\a')
k=k.replace('\b','\\b')
k=k.replace('\f','\\f')
k=k.replace('\n','\\n')
k=k.replace('\r','\\r')
k=k.replace('\t','\\t')
k=k.replace('\v','\\v')
return k

Here is a straightforward solution.
address = 'C:\Windows\Users\local'
directory ="r'"+ address +"'"
print(directory)
"r'C:\\Windows\\Users\\local'"

Python2.7 set a given variable to replace one backslash to two backslashes

I'm still new to programming and working on my first python script.
I'm trying to make my python script execute in a way so the user only has to type this:
script.py \\server\location
and not execute this this
script.py \\\\server\\location
Here is what I have so far:
import sys
buildpath = sys.argv[1]
buildpath.replace(r'\\', r'\\\\')
print buildpath
Any help with this is much appreciated :)

You are not capturing the changed buildpath variable after calling .replace(). .replace() returns the new string; strings are immutable so .replace() cannot change buildpath in-place.
Next, you are using raw strings to define double slashes, but you wanted to replace single slashes. Remove the r from r'\\' and r'\\\\'; you cannot use a single slash as the last character in a raw string literal anyway.
I think you wanted to do this instead:
buildpath = sys.argv[1]
buildpath = buildpath.replace('\\', '\\\\')
print buildpath

How to write string literals in Python without having to escape them?

Is there a way to declare a string variable in Python such that everything inside of it is automatically escaped, or has its literal character value?
I'm not asking how to escape the quotes with slashes, that's obvious. What I'm asking for is a general purpose way for making everything in a string literal so that I don't have to manually go through and escape everything for very large strings.

Raw string literals:
>>> r'abc\dev\t'
'abc\\dev\\t'

If you're dealing with very large strings, specifically multiline strings, be aware of the triple-quote syntax:
a = r"""This is a multiline string
with more than one line
in the source code."""

There is no such thing. It looks like you want something like "here documents" in Perl and the shells, but Python doesn't have that.
Using raw strings or multiline strings only means that there are fewer things to worry about. If you use a raw string then you still have to work around a terminal "\" and with any string solution you'll have to worry about the closing ", ', ''' or """ if it is included in your data.
That is, there's no way to have the string
' ''' """ " \
properly stored in any Python string literal without internal escaping of some sort.

You will find Python's string literal documentation here:
http://docs.python.org/tutorial/introduction.html#strings
and here:
http://docs.python.org/reference/lexical_analysis.html#literals
The simplest example would be using the 'r' prefix:
ss = r'Hello\nWorld'
print(ss)
Hello\nWorld

(Assuming you are not required to input the string from directly within Python code)
to get around the Issue Andrew Dalke pointed out, simply type the literal string into a text file and then use this;
input_ = '/directory_of_text_file/your_text_file.txt'
input_open = open(input_,'r+')
input_string = input_open.read()
print input_string
This will print the literal text of whatever is in the text file, even if it is;
' ''' """ “ \
Not fun or optimal, but can be useful, especially if you have 3 pages of code that would’ve needed character escaping.

Use print and repr:
>>> s = '\tgherkin\n'
>>> s
'\tgherkin\n'
>>> print(s)
gherkin
>>> repr(s)
"'\\tgherkin\\n'"
# print(repr(..)) gets literal
>>> print(repr(s))
'\tgherkin\n'
>>> repr('\tgherkin\n')
"'\\tgherkin\\n'"
>>> print('\tgherkin\n')
gherkin
>>> print(repr('\tgherkin\n'))
'\tgherkin\n'

regarding backslash from postgresql

i have a noob question.
I have a record in a table that looks like '\1abc'
I then use this string as a regex replacement in re.sub("([0-9])",thereplacement,"2")
I'm a little confused with the backslashes. The string i got back was "\\1abc"

Are you using python interactivly?
In regular string you need to escape backslashes in your code, or use r"..." (Link to docs). If you are running python interactivly and don't assign the results from your database to a variable, it'll be printed out using it's __repr__() method.
>>> s = "\\1abc"
>>> s
'\\1abc' # <-- How it's represented in Python code
>>> print s
\1abc # <-- The actual string
Also, your re.sub is a bit weird. 1) Maybe you meant [0-9] as the pattern? (Matching a single digit). The arguments are probably switche too, if thereplacement is your input. This is the syntax:
re.sub(pattern, repl, string, count=0)
So my guess is you expect something like this:
>>> s_in = yourDbMagic() # Which returns \1abc
>>> s_out = re.sub("[0-9]", "2", s_in)
>>> print s_in, s_out
\1abc \2abc
Edit: Tried to better explain escaping/representation.

Note that you can make \ stop being an escape character by setting standard_conforming_strings to on.