Python: Way to speed up a repeatedly executed eval statement?

Question

In my code, I\'m using eval to evaluate a string expression given by the user. Is there a way to compile or otherwise speed up this statement?

Answer 1

You can also trick python:

expression = "math.sin(v['x']) * v['y']"
exp_as_func = eval('lambda: ' + expression)

And then use it like so:

exp_as_func()

Speed test:

In [17]: %timeit eval(expression)
10000 loops, best of 3: 25.8 us per loop

In [18]: %timeit exp_as_func()
1000000 loops, best of 3: 541 ns per loop

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As a side note, if v is not a global, you can create the lambda like this:

exp_as_func = eval('lambda v: ' + expression)

and call it:

exp_as_func(my_v)