How do you read a lambda function as a string?

Edit: Changed my first answer as I misunderstood the question. This answer is borrowed from a number of other uses, however I have completed the code to only display the part of the string that you want.

import inspect

func = lambda num1,num2: num1 + num2
funcString = str(inspect.getsourcelines(func)[0])
funcString = funcString.strip("['\\n']").split(" = ")[1]
print funcString

Outputs the following string:

lambda num1,num2: num1 + num2

You can use Python's eval() function:

>>> func = eval('lambda num1,num2: num1 + num2')
>>> func
<function <lambda> at 0x7fe87b74b668>

To evaluate any expression and return the value.

You can use getsourcelines from the inspect module to do this

This function returns as a list all of the lines of the definition of any function, module, class or method as well as the line number at which it was defined.

For example:

import inspect

f = lambda x, y : x + y

print inspect.getsourcelines(f)[0][0]

Will output the definition of the function as:

f = lambda x, y: x + y