Short strings in Python are interned, i.e. 'foo' always returns the same string, not just an identical one. There's some noise but the important part is that b

Short strings in Python are interned, i.e. 'foo' always returns the same string, not just an identical one. There's some noise but the important part is that both x and y have the same address (0x37e300) and point to the same str object. Python 2.6.4 (r264:75706, Nov 25 2009, 21:38:24) [GCC 4.2.1 (Apple Inc. build 5646) (dot 1)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> x='foo' >>> y='foo' >>> x.__add__ <method-wrapper '__add__' of str object at 0x37e300> >>> y.__add__ <method-wrapper '__add__' of str object at 0x37e300> >>> x is y True and a counter-example just for fun: >>> x='this is a longer string. i wonder what the limit is?!' >>> y='this is a longer string. i wonder what the limit is?!' >>> x.__add__ <method-wrapper '__add__' of str object at 0x35a840> >>> y.__add__ <method-wrapper '__add__' of str object at 0x35a890> >>> x is y False