# escaping – How can I selectively escape percent (%) in Python strings?

## The Question :

387 people think this question is useful

I have the following code

test = "have it break."
selectiveEscape = "Print percent % in sentence and not %s" % test

print(selectiveEscape)



I would like to get the output:

Print percent % in sentence and not have it break.



What actually happens:

    selectiveEscape = "Use percent % in sentence and not %s" % test
TypeError: %d format: a number is required, not str


• Why isn’t it \%? That was my guess, I’m surprised to find it’s %% instead – seems pretty counterintuitive.
• % i means “a decimal representation of an integer, padded left with spaces.
• The escape is to the function, not the language syntax. Hence if the escape was \% it would actually be \\% when written in ordinary code. <escape><escape> is the typical pattern I’ve seen, and \ happens to be the most common escape character, for better or worse.
• @Demis and how do you escape \  if you had to print \\%? You are bound to require escaping through repetition of special characters, if the special characters are also not special depending on circumstances.
• I think it is annoying in Python that the the literal % is encoded by “%%” and not by “\%”.

662 people think this answer is useful
>>> test = "have it break."
>>> selectiveEscape = "Print percent %% in sentence and not %s" % test
>>> print selectiveEscape
Print percent % in sentence and not have it break.



58 people think this answer is useful

Alternatively, as of Python 2.6, you can use new string formatting (described in PEP 3101):

'Print percent % in sentence and not {0}'.format(test)



which is especially handy as your strings get more complicated.

40 people think this answer is useful

try using %% to print % sign .

5 people think this answer is useful

You can’t selectively escape %, as % always has a special meaning depending on the following character.

In the documentation of Python, at the bottem of the second table in that section, it states:

'%'        No argument is converted, results in a '%' character in the result.



Therefore you should use:

selectiveEscape = "Print percent %% in sentence and not %s" % (test, )



(please note the expicit change to tuple as argument to %)

Without knowing about the above, I would have done:

selectiveEscape = "Print percent %s in sentence and not %s" % ('%', test)



3 people think this answer is useful

If the formatting template was read from a file, and you cannot ensure the content doubles the percent sign, then you probably have to detect the percent character and decide programmatically whether it is the start of a placeholder or not. Then the parser should also recognize sequences like %d (and other letters that can be used), but also %(xxx)s etc.

Similar problem can be observed with the new formats — the text can contain curly braces.

1 people think this answer is useful

If you are using Python 3.6 or newer, you can use f-string:

>>> test = "have it break."
>>> selectiveEscape = f"Print percent % in sentence and not {test}"
>>> print(selectiveEscape)
... Print percent % in sentence and not have it break.



-3 people think this answer is useful

I have tried different methods to print a subplot title, look how they work. It’s different when i use Latex.

It works with ‘%%’ and ‘string’+’%’ in a typical case.

If you use Latex it worked using ‘string’+’\%’

So in a typical case:

import matplotlib.pyplot as plt
fig,ax = plt.subplots(4,1)
float_number = 4.17
ax[0].set_title('Total: (%1.2f' %float_number + '\%)')
ax[1].set_title('Total: (%1.2f%%)' %float_number)
ax[2].set_title('Total: (%1.2f' %float_number + '%%)')
ax[3].set_title('Total: (%1.2f' %float_number + '%)')



Title examples with %

If we use latex:

import matplotlib.pyplot as plt
import matplotlib
font = {'family' : 'normal',
'weight' : 'bold',
'size'   : 12}
matplotlib.rc('font', **font)
matplotlib.rcParams['text.usetex'] = True
matplotlib.rcParams['text.latex.unicode'] = True
fig,ax = plt.subplots(4,1)
float_number = 4.17
#ax[0].set_title('Total: (%1.2f\%)' %float_number) This makes python crash
ax[1].set_title('Total: (%1.2f%%)' %float_number)
ax[2].set_title('Total: (%1.2f' %float_number + '%%)')
ax[3].set_title('Total: (%1.2f' %float_number + '\%)')



We get this: Title example with % and latex