如何使用Python在Bytes中获取UTF-8字符串的大小

Question

Having an UTF-8 string like this:

mystring = "işğüı"

is it possible to get its (in memory) size in Bytes with Python (2.5)?

Answer 1

Assuming you mean the number of UTF-8 bytes (and not the extra bytes that Python requires to store the object), it's the same as for the length of any other string. A string literal in Python 2.x is a string of encoded bytes, not Unicode characters.

Byte strings:

>>> mystring = "işğüı"
>>> print "length of {0} is {1}".format(repr(mystring), len(mystring))
length of 'i\xc5\x9f\xc4\x9f\xc3\xbc\xc4\xb1' is 9

Unicode strings:

>>> myunicode = u"işğüı"
>>> print "length of {0} is {1}".format(repr(myunicode), len(myunicode))
length of u'i\u015f\u011f\xfc\u0131' is 5

It's good practice to maintain all of your strings in Unicode, and only encode when communicating with the outside world. In this case, you could use len(myunicode.encode('utf-8')) to find the size it would be after encoding.