ImportError：无法导入名称错误

Question

I have a very simple test function that I need to capture its execution time using 'timeit' module, but I get an error

The function:

import timeit
def test1():                            
    l = []
    for i in range(1000):
        l = l + [i]

t1 = timeit.Timer("test1()", "from __main__ import test1")
print(t1.timeit(number=1000))

The Error: C:\\Python34\\lib\\timeit.py:186: in timeit timing = self.inner(it, self.timer) :3: in inner ??? E
ImportError: cannot import name 'test1' =========== 1 error in 0.03 seconds ==============

Can you guys help me with a solution?

Answer 1

I think there are couple of problems with your code. First for all make sure you can import timeit. And you have it as a module. For this, you can just run:

 python -m timeit '"-".join(str(n) for n in range(100))'

If it execute fine then you sure have the timeit module.

Now regarding your question. I took the liberty to rewriting it in a cleaner way.

import timeit    

def append_list():
 num_list = []
 for i in range(1000):
         num_list.append(i)

print(timeit.timeit(stmt=append_list, number=1000)) #number is the number of repetion of the operation, in this case, 1000
# you can also run
print(timeit.timeit(stmt=append_list, number=1))   

Now, the above could will do what you wanted to do, ie calculate the amount of time required to append numbers from 1 to 1000 to the list.