How do you ignore a slash in python?

This one is a bit tricky I think.

if I have:

a = "fwd"
b = "\fwd"

how can I ignore the "\" so something like

print[a in b]

can evaluate to True?

asked Apr 14, 2016 at 13:00

You don't have fwd in b. You have wd, preceded by ASCII codepoint 0C, the FORM FEED character. That's the value Python puts there when you use a \f escape sequence in a regular string literal.

Double the backslash if you want to include a backslash or use a raw string literal:

b = '\\fwd'
b = r'\fwd'

Now a in b works:

>>> 'fwd' in '\\fwd'
True
>>> 'fwd' in r'\fwd'
True

See the String literals documentation:

Unless an 'r' or 'R' prefix is present, escape sequences in strings are interpreted according to rules similar to those used by Standard C. The recognized escape sequences are:
[...]
\f ASCII Formfeed [FF]

jfs

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answered Apr 14, 2016 at 13:05

Martijn Pieters♦Martijn Pieters

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One way of doing it using raw strings:

>>> a = "fwd"
>>> b = "\fwd"
>>> a in b
False
>>> a = r"fwd"
>>> b = r"\fwd"
>>> a in b
True

The relevant docs

answered Apr 14, 2016 at 13:04

jDojDo

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You need to "escape" the backslash, as in:

b = '\\fwd'

Otherwise, it reads the single backslash + f as an ASCII character [a formfeed].

Here's an example.

>>> a='fwd'
>>> b='\fwd'
>>> c='\\fwd'
>>> a in b
False
>>> a in c
True

answered Apr 14, 2016 at 13:05

rajah9rajah9

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Summary: in this tutorial, you’ll learn about the Python backslash character as a part of a special sequence character or to escape characters in a string.

Introduction to the Python backslash

In Python, the backslash[\] is a special character. If you use the backslash in front of another character, it changes the meaning of that character.

For example, the t is a literal character. But if you use the backslash character in front of the letter t, it’ll become the tab character [\t].

Generally, the backslash has two main purposes.

First, the backslash character is a part of special character sequences such as the tab character \t or the new line character \n.

The following example prints a string that has a newline character:

print['Hello,\n World']
Code language: PHP [php]

Output:

Hello, World

The \n is a single character, not two. For example:

s = '\n'
print[len[s]] # 1
Code language: PHP [php]

Second, the backslash [\] escape other special characters. For example, if you have a string that has a single quote inside a single-quoted string like the following string, you need to use the backslash to escape the single quote character:

s = '"Python\'s awesome" She said'
print[s]
Code language: PHP [php]

Output:

"Python's awesome" She said
Code language: JavaScript [javascript]

Backslash in f-strings

PEP-498 specifies that an f-string cannot contain a backslash character as a part of the expression inside the curly braces {}.

The following example will result in an error:

colors = ['red','green','blue']
s = f'The RGB colors are:\n {'\n'.join[colors]}'
print[s]
Code language: PHP [php]

Error:

SyntaxError: f-string expression part cannot include a backslash

Code language: JavaScript [javascript]

To fix this, you need to join the strings in the colors list before placing them in the curly braces:

colors = ['red','green','blue']
rgb = '\n'.join[colors]
s = f"The RGB colors are:\n{rgb}"
print[s]
Code language: PHP [php]

Output:

The RGB colors are: red green blue

Backslash in raw strings

Raw strings treat the backslash character [\] as a literal character. The following example treats the backslash character \ as a literal character, not a special character:

s = r'\n'
print[s]
Code language: PHP [php]

Output:

\n

Summary

The python backslash character [\] is a special character used as a part of a special sequence such as \t and \n.
Use the Python backslash [\] to escape other special characters in a string.
F-strings cannot contain the backslash a part of expression inside the curly braces {}.
Raw strings treat the backslash [\] as a literal character.

Did you find this tutorial helpful ?

How do you escape a slash in Python?

Learn More. In Python strings, the backslash "\" is a special character, also called the "escape" character. It is used in representing certain whitespace characters: "\t" is a tab, "\n" is a newline, and "\r" is a carriage return. Conversely, prefixing a special character with "\" turns it into an ordinary character.

How do you ignore a character in Python?

“python string ignore characters” Code Answer.

text = ['! kick', '/ban', '! k! ck'].

for s in text:.

print s[0]. translate[None, '!/'] + s[1:].

output:.

k! ck..

How do you ignore a special character in a string in Python?

To insert characters that are illegal in a string, use an escape character. An escape character is a backslash \ followed by the character you want to insert.

Introduction to the Python backslash

Backslash in f-strings

Backslash in raw strings

Summary

How do you escape a slash in Python?

How do you ignore a character in Python?

How do you ignore a special character in a string in Python?

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