Cannot make cProfile work in IPython
Question
I'm missing something very basic.
class C:
def __init__(self):
self.N = 100
pass
def f(self, param):
print 'C.f -- param'
for k in xrange(param):
for i in xrange(self.N):
for j in xrange(self.N):
a = float(i)/(1+float(j)) + float(i/self.N) ** float(j/self.N)
import cProfile
c = C()
cProfile.run('c.f(3)')
When I run the above code in IPython, I get:
NameError: name 'c' is not defined
What am I missing?
UPDATE the exact paste of my session is here: http://pastebin.com/f3e1b9946
UPDATE I didn't mention that the problem occurs in IPython, which (at it turns out) is the source of the problem
Solution
While inside IPython, you can use the %prun magic function:
In [9]: %prun c.f(3)
C.f -- param
3 function calls in 0.066 CPU seconds
Ordered by: internal time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.066 0.066 0.066 0.066 <string>:6(f)
1 0.000 0.000 0.066 0.066 <string>:1(<module>)
1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}
OTHER TIPS
Not the original poster's problem, but you can also get this same error if you are invoking cProfile.run() in something other than the __main__ namespace (from within a function or an import). In that case you need to use the following instead of the run() method:
cProfile.runctx("your code", globals(), locals())
Kudos to this post for helping me figure this out.
Although IPython is very handy, there is a lot of rare cases when it breaks working code or masks errors. So it's useful to try code in standard interpreter when you get such mystical errors.