I can't find .join function on http://docs.python.org/

string.join - so it’s in the document about string http://docs.python.org/2/library/string.html#string.join

if it was a built-in it would be join, not .join there’s always a name before the dot

and the built-ins are here: http://docs.python.org/2/library/functions.html

index of standard library: http://docs.python.org/2/library/index.html

and then there are 3rd party libraries, those docs are elsewhere

and this one is good to be aware about: http://www.python.org/dev/peps/pep-0008/

oh. oops. what you wanted was str.join, not string.join.. wasn’t even aware they both existed until now >_< THIS is str.join!

there’s a module called string a module is just another .py file that is run when you use the import statement the module string contains a couple of functions and classes a string is an instance of one of those classes (str or unicode) those classes contain methods, methods are functions that are defined in classes

str is a class string is a module

str.join is a method of the value type str string.join is a function in the module string

some code to show the difference between those two:

string.join:

import string
string.join(['bob', 'peter'], ' ') # evaluates into 'bob peter'

^join is a function in the module string, that’s why string needs to be imported, if instead doing: from string import join then string. would not be necessary

str.join:

' '.join(['bob', 'peter']) # evaluates into 'bob peter'

^’ ‘ is an instance of str, str contains the method join which can be called on ‘ ‘