How to get the size of a string in Python?
Python 3:
user225312's answer is correct:
A. To count number of characters in str
object, you can use len()
function:
>>> print(len('please anwser my question'))
25
B. To get memory size in bytes allocated to store str
object, you can use sys.getsizeof()
function
>>> from sys import getsizeof
>>> print(getsizeof('please anwser my question'))
50
Python 2:
It gets complicated for Python 2.
A. The len()
function in Python 2 returns count of bytes allocated to store encoded characters in a str
object.
Sometimes it will be equal to character count:
>>> print(len('abc'))
3
But sometimes, it won't:
>>> print(len('йцы')) # String contains Cyrillic symbols
6
That's because str
can use variable-length encoding internally. So, to count characters in str
you should know which encoding your str
object is using. Then you can convert it to unicode
object and get character count:
>>> print(len('йцы'.decode('utf8'))) #String contains Cyrillic symbols
3
B. The sys.getsizeof()
function does the same thing as in Python 3 - it returns count of bytes allocated to store the whole string object
>>> print(getsizeof('йцы'))
27
>>> print(getsizeof('йцы'.decode('utf8')))
32
If you are talking about the length of the string, you can use len()
:
>>> s = 'please answer my question'
>>> len(s) # number of characters in s
25
If you need the size of the string in bytes, you need sys.getsizeof()
:
>>> import sys
>>> sys.getsizeof(s)
58
Also, don't call your string variable str
. It shadows the built-in str()
function.