In Python, a string [str] is created by enclosing text in single quotes ', double quotes ", and triple quotes [''', """]. It is also possible to convert objects of other types to strings with str[].
- Built-in Types - Text Sequence Type — str — Python 3.10.0 documentation
This article describes the following contents.
- Single quotes:
' - Double quotes:
" - Difference between single quotes and double quotes
- Both values are equal
- Quotes in strings are handled differently
- Triple quotes:
''',"""- Multiple lines
- Single and double quotes
- Indentation
- Convert other types to strings:
str[]- Convert numbers to strings
- Convert lists and dictionaries to strings
Single quotes: '
Enclose the text in single quotes ' to make it a string [str].
s = 'abc'
print[s]
# abc
print[type[s]]
#
Double quotes: "
Also, enclose the text in double quotes " to make it a string [str].
s = "abc"
print[s]
# abc
print[type[s]]
#
Difference between single quotes and double quotes
Both values are equal
Whether you use single
quotes ' or double quotes ", created strings are equal.
s_sq = 'abc'
s_dq = "abc"
print[s_sq == s_dq]
# True
Quotes in strings are handled differently
In a string enclosed in single quotes ', double quotes " can be used as is, but single quotes ' must be escaped with a backslash and written as \'. There is no problem if you write \" for double quotes ".
s_sq = 'a\'b"c'
print[s_sq]
# a'b"c
s_sq = 'a\'b\"c'
print[s_sq]
# a'b"c
In a string enclosed in double quotes
", single quotes ' can be used as is, but double quotes " must be escaped with a backslash and written as \". There is no problem if you write \' for single quotes '.
s_dq = "a'b\"c"
print[s_dq]
# a'b"c
s_dq = "a\'b\"c"
print[s_dq]
# a'b"c
Since it is just a difference in writing, values are equal in both cases.
s_sq = 'a\'b"c'
s_dq = "a'b\"c"
print[s_sq == s_dq]
# True
Triple quotes: ''', """
Triple quotes [''', """], that is, three single quotes ' or double quotes ",
also make a string [str].
Multiple lines
An error occurs when a newline is inserted in a string enclosed in single or double quotes. To insert a newline, you need to use \n.
- Handle line breaks [newlines] in Python
# s = 'abc
# xyz'
# SyntaxError: EOL while scanning string literal
s = 'abc\nxyz'
print[s]
# abc
# xyz
Within a string enclosed in triple quotes, line breaks can be written as they are.
s_tq = '''abc
xyz'''
print[s_tq]
# abc
# xyz
print[type[s_tq]]
#
Of course, it does not have to contain line breaks.
s_tq = '''abc'''
print[s_tq]
# abc
Single and double quotes
You can use " in three single quotes ''' and ' in three double quotes """. Values are equal in both cases.
s_tq_sq = '''\'abc\'
"xyz"'''
print[s_tq_sq]
# 'abc'
# "xyz"
s_tq_dq = """'abc'
\"xyz\""""
print[s_tq_dq]
# 'abc'
# "xyz"
print[s_tq_sq == s_tq_dq]
# True
Indentation
If spaces are inserted at the beginning of a line to match the indentation, created string includes spaces.
s_tq = '''abc
xyz'''
print[s_tq]
# abc
# xyz
There is a way to write the following using line feed and parentheses.
s_multi = ['abc\n'
'xyz']
print[s_multi]
# abc
# xyz
See the following article for details.
- Handle line breaks [newlines] in Python
Convert other types to strings: str[]
You can use str[] to convert objects of other types to strings [str].
- Built-in Types -str[] — Python 3.10.0 documentation
str[] returns the result of the __str[]__ method of the target object. If its type has no __str[]__ method defined, it returns the result of repr[].
The following are some examples of typical types.
Convert numbers to strings
Integers int and floating point numbers float can be converted to strings str with str[].
i = 100
s_i = str[i]
print[s_i]
# 100
print[type[s_i]]
#
f = 0.123
s_f = str[f]
print[s_f]
# 0.123
print[type[s_f]]
#
For example, int can be written
in hexadecimal, float in exponential, and so on, but when converted to a string with str[], they are converted to standard decimal strings.
i = 0xFF
print[i]
# 255
s_i = str[i]
print[s_i]
# 255
f = 1.23e+10
print[f]
# 12300000000.0
s_f = str[f]
print[s_f]
# 12300000000.0
Use the built-in function format[] to convert it to a string of the desired format.
- Built-in Functions - format[] — Python 3.10.0 documentation
s_i_format = format[i, '#X']
print[s_i_format]
# 0XFF
s_f_format = format[f, '.2e']
print[s_f_format]
# 1.23e+10
If you want to convert a string of numbers to numeric values, see the following article.
- Convert a string to a number [int, float] in Python
Convert lists and dictionaries to strings
Lists list and dictionaries dict can also be converted to strings str with str[].
l = [0, 1, 2]
s_l = str[l]
print[s_l]
# [0, 1, 2]
print[type[s_l]]
#
d = {'a': 1,
'b': 2,
'c': 3}
s_d = str[d]
print[s_d]
# {'a': 1, 'b': 2, 'c': 3}
print[type[s_d]]
You can use pformat[] of the pprint module of the standard library to convert it to a
well-formed string.
import pprint
dl = {'a': 1, 'b': 2, 'c': [100, 200, 300]}
s_dl = str[dl]
print[s_dl]
# {'a': 1, 'b': 2, 'c': [100, 200, 300]}
p_dl = pprint.pformat[dl, width=10]
print[p_dl]
# {'a': 1,
# 'b': 2,
# 'c': [100,
# 200,
# 300]}
print[type[p_dl]]
#
For more information about pprint, see the following article.
- Pretty-print with pprint in Python