Getting "global name 'foo' is not defined" with Python's timeit
PythonScopeTimeitPython Problem Overview
I'm trying to find out how much time it takes to execute a Python statement, so I looked online and found that the standard library provides a module called timeit that purports to do exactly that:
import timeit
def foo():
# ... contains code I want to time ...
def dotime():
t = timeit.Timer("foo()")
time = t.timeit(1)
print "took %fs\n" % (time,)
dotime()
However, this produces an error:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 3, in dotime
File "/usr/local/lib/python2.6/timeit.py", line 193, in timeit
timing = self.inner(it, self.timer)
File "<timeit-src>", line 6, in inner
NameError: global name 'foo' is not defined
I'm still new to Python and I don't fully understand all the scoping issues it has, but I don't know why this snippet doesn't work. Any thoughts?
Python Solutions
Solution 1 - Python
Change this line:
t = timeit.Timer("foo()")
To this:
t = timeit.Timer("foo()", "from __main__ import foo")
Check out the link you provided at the very bottom.
> To give the timeit module access to functions you define, you can pass a setup parameter which contains an import statement:
I just tested it on my machine and it worked with the changes.
Solution 2 - Python
With Python 3, you can use globals=globals()
t = timeit.Timer("foo()", globals=globals())
From the documentation:
> Another option is to pass globals()
to the globals
parameter, which
> will cause the code to be executed within your current global
> namespace. This can be more convenient than individually specifying
> imports
Solution 3 - Python
You can try this hack:
import timeit
def foo():
print 'bar'
def dotime():
t = timeit.Timer("foo()")
time = t.timeit(1)
print "took %fs\n" % (time,)
import __builtin__
__builtin__.__dict__.update(locals())
dotime()
Solution 4 - Python
t = timeit.Timer("foo()", "from __main__ import foo")
Since timeit doesn't have your stuff in scope.
Solution 5 - Python
add into your setup "import thisfile; "
then when you call the setup function myfunc() use "thisfile.myfunc()"
eg "thisfile.py"
def myfunc():
return 5
def testable(par):
pass
t=timeit.timeit(stmt="testable(v)",setup="import thisfile; v=thisfile.myfunc();").repeat(10)
print( t )