This question already has answers here:
How can I put an actual backslash in a string literal (not use it for an escape sequence)?
(4 answers)
Closed 4 years ago.
When I try to use
print variable + "\filename"
the slash isn't recognized as a string character,
however if I were to do
print variable + "\Filename"
capitalizing the first letter proceeding the slash... then the slash is recognized as a string character
The only thing I was able to find online is that in some cases a \ with a letter preceding it may be used to end a string of raw characters but I don't understand this.
So my question is why does this happen? And more importantly what is a way around this or a fix for this. Thank you.
You need to mark it as raw with the prefix r. Like this: print variable + r"\filename" Or alternatively you can escape it using a backslash print variable + "\\filename"
Related
This question already has answers here:
How can I put an actual backslash in a string literal (not use it for an escape sequence)?
(4 answers)
Closed 1 year ago.
I need to split a string that I receive like that :
my_string = "\data\details\350.23.43.txt"
when I use my_string.replace ("\\", "/")
it returns : /data/detailsè.23.43.txt
It's considering the \350 in my string as a special character 'è'
Edit after your comment:
Try
my_string = r"\data\details\350.23.43.txt"
That happens because \ooo is interpreted as a character with octal value as described in the docs.
I guess the only way is to escape the \ as in:
my_string = "\data\details\\350.23.43.txt"
Then you can do stuff like:
my_string.split("\\")
Where do you get the string from? Is there a way to influence that?
And this looks like a path. It would be better to use
os.path.join("data", "details", "350.23.43.txt")
to create paths independently of the operating system.
\ in string literals are treated as escaping chars. That is why s1 = "line\nsecond line" creates a string with two lines. That is also why you use "\\" in my_string.replace ("\\", "/").
So to fix your problem, if you're using a string literal my string = "\data\details\350.23.43.txt" you should instead use "\\data\\details\\350.23.43.txt" to make sure your \ are properly escaped. Alternatively, you can use a raw string my string = r"\data\details\350.23.43.txt" by prepending r to the quote. That way nothing gets escaped (so r"\n" would be a 2 char string with \ and n instead of just a single new line char)
This question already has answers here:
Does a dot have to be escaped in a character class (square brackets) of a regular expression?
(1 answer)
What special characters must be escaped in regular expressions?
(13 answers)
Closed 2 years ago.
For teaching purposes, I would like a good explanation and example of why the "\" is needed in searching for, say a period or a character that python may interpret differently.
In the below example, I do NOT use a "\" to escape the "." and it still works fine.
def checkfordot():
dotpattern="[.]"
searchingfor=input("Enter string:")
if (re.search(dotpattern,searchingfor)):
print("Has a dot")
else:
print("Does not have a dot")
Output:
>>> checkfordot()
Enter string:dfsdf.
Has a dot
>>> checkfordot()
Enter string:ffsdfsdfsdf
Does not have a dot
>>>
In this case, using dotpattern="[.]" or dotpattern="[.]" doesn't seem to make much difference.
Can someone a) explain why the above works without an escape and a simple explanation of what the escape does and in what situations b) provide an example or ideally two examples, integrated into my code, that demonstrates well why the escape character is required and how it is used for effective searching (or vice versa, in that without the "" the program would not work)
Ironically, in typing this out - I noticed I had to escape the \ in order for it to be printed. Here I am typing: >: " \ \ " ....but it prints just one backslash >"\"
This question already has answers here:
python replace backslashes to slashes
(3 answers)
Closed 3 years ago.
I need to replace a python string that contains a number of '\':
String = 'A\BBC\CCB\:ABC'
goal = 'A/BBC/CCB/:ABC'
num = String.count('\')
String.replace('\','/')
But I keep getting error message:
SyntaxError: EOL while scanning string literal
The \ character in python has special uses. Eg. "\n" (newLine Character). In order to replace it in a string, you need to use one of the following:
String.replace('\\','/')
String.replace(r'\','/')
The "\" will look for the "\" character.
The r'\' will look for the raw interpretation of the string '\'
In your case you can do it like this:
string.replace('\\', '/', num)
Use '\', consider this situation:
print( "He said: \"Something about her.\"" );
This question already has answers here:
How can I put an actual backslash in a string literal (not use it for an escape sequence)?
(4 answers)
Closed 8 years ago.
I program in Python in PyCharm and whenever I write '\' as a string it says that the following statements do nothing. For example:
Is there a way to fix this and make it work?
Thanks.
You need to double the backslash:
'/-\\'
as a single backslash has special meaning in a Python string as the start of an escape sequence. A double \\ results in the string containing a single backslash:
>>> print '/-\\'
/-\
If the backslash is not the last character in the string, you could use a r'' raw string as well:
>>> print r'\-/'
\-/
You need to scape them to be in the string, for example:
>>>s='\\'
>>>print s
\
You can also use the r (raw string) modifier in front of the string to include them easily but they can't end with an odd number of backslash. You can read more about string literals on the docs.
This question already has answers here:
How can I print a single backslash?
(4 answers)
Closed 7 months ago.
How can I compare if a backslash is in my string?
I don't know how to write the backslash symbol to compare it.
I try this but don't work:
Code:
s = r"\""
print s
Output: \"
If I try s = "\"" it gives " as output
I don't know how to acheive that.
Thanks for any help.
You need to escape the backslash.
s = "\\"
>>>mystring = "can python find this backslash \n"
>>>"\\" in r"%r" % mystring
True
while trying to filter the backslash \ character from being used in Windows filenames I searched a lot of places for answers. this is the solution worked for me.
based on information I read at...
http://pythonconquerstheuniverse.wordpress.com/2008/06/04/gotcha-%E2%80%94-backslashes-in-windows-filenames/
Backslashes are used for escaping, so to display a backslash in a string literal you need to escape the backslash with another backslash.
print "\\"
prints a string with 1 backslash.
"\\" in mystring
Where mystring is your string. Will tell you if it contains a backslash