Opening this bug at Ben Finney's request.  See https://groups.google.com/forum/?fromgroups#!topic/comp.lang.python/wmDUrpW2ZCU for the full thread discussing the problem.  Here's a significant excerpt:

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The tutorial is misleading on this. It it says plainly: 

    A module can contain executable statements as well as function 
    definitions. […] They are executed only the *first* time the module 
    is imported somewhere. 

    <URL:http://docs.python.org/tutorial/modules.html> 

but it doesn't make clear that a module can exist in the ‘sys.modules’ 
list multiple times under different names. 
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Also note:

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The footnote to that is wrong too: 

> [1]        In fact function definitions are also ‘statements’ that are ‘executed’; the execution of a module-level function enters the function name in the module’s global symbol table. 

I think what it's supposed to say is "... the execution of a module-level def statement ..." 
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Well, I don't think a full discussion of the subtlety about a module appearing under multiple names belongs in the tutorial, but I think the sentence could be amended to say "Statements in a module are executed only the *first* time the module name is encountered in an import statement".

The other is indeed a bug (IMO the sentence is missing the word 'definition', as in 'execution of a function definition').

Howdy; attached is a patch containing the doc changes. I figured that some elaboration was in addition to what r.david.murray recommended, so I've included a brief allusion to the problem of equivalent paths.

New changeset 9df9931fae96 by R David Murray in branch '3.3':
#15575: Clarify tutorial description of when modules are executed.
http://hg.python.org/cpython/rev/9df9931fae96

New changeset dac847938326 by R David Murray in branch 'default':
#15575: Clarify tutorial description of when modules are executed.
http://hg.python.org/cpython/rev/dac847938326

New changeset a1421d28393b by R David Murray in branch '2.7':
#15575: Clarify tutorial description of when modules are executed.
http://hg.python.org/cpython/rev/a1421d28393b

Thanks, James.  I wound up going with a different wording for the "elaboration": since the concept of running a python file as a script is mentioned just a bit earlier, I added a parenthetical that the statements are also executed if the module is run as a script.