Issue
Using the inspect.getsourcelines function, I have been able to get a Python function’s source code like this:
import inspect
def some_decorator(x):
return x
@some_decorator
def foo():
print("bar")
print(inspect.getsourcelines(foo)[0])
This code will correctly output the source lines of the function as a list:
['@some_decorator\n', 'def foo():\n', ' print("bar")\n']
However, I only want the code inside the function, not the entire function declaration. So I only want this output (noting also the correct indentation):
['print("bar")\n']
I have attempted to do this using a slice and a strip to remove the first two lines and then remove indentation, but this wouldn’t work with many functions and I have to believe there’s a better way.
Does the inspect module, or another module which I can pip install, have this functionality?
Solution
You can do something like this:
import inspect
from itertools import dropwhile
def get_function_body(func):
source_lines = inspect.getsourcelines(func)[0]
source_lines = dropwhile(lambda x: x.startswith('@'), source_lines)
def_line = next(source_lines).strip()
if def_line.startswith('def ') and def_line.endswith(':'):
# Handle functions that are not one-liners
first_line = next(source_lines)
# Find the indentation of the first line
indentation = len(first_line) - len(first_line.lstrip())
return ''.join([first_line[indentation:]] + [line[indentation:] for line in source_lines])
else:
# Handle single line functions
return def_line.rsplit(':')[-1].strip()
Demo:
def some_decorator(x):
return x
@some_decorator
def foo():
print("bar")
def func():
def inner(a, b='a:b'):
print (100)
a = c + d
print ('woof!')
def inner_inner():
print (200)
print ('spam!')
return inner
def func_one_liner(): print (200); print (a, b, c)
print (get_function_body(foo))
print (get_function_body(func()))
print (get_function_body(func_one_liner))
func_one_liner = some_decorator(func_one_liner)
print (get_function_body(func_one_liner))
Output:
print("bar")
print (100)
a = c + d
print ('woof!')
def inner_inner():
print (200)
print ('spam!')
print (200); print (a, b, c)
print (200); print (a, b, c)
Update:
To handle async and functions with multiline argument signature get_function_body should be updated to:
import inspect
import re
from itertools import dropwhile
def get_function_body(func):
print()
print("{func.__name__}'s body:".format(func=func))
source_lines = inspect.getsourcelines(func)[0]
source_lines = dropwhile(lambda x: x.startswith('@'), source_lines)
source = ''.join(source_lines)
pattern = re.compile(r'(async\s+)?def\s+\w+\s*\(.*?\)\s*:\s*(.*)', flags=re.S)
lines = pattern.search(source).group(2).splitlines()
if len(lines) == 1:
return lines[0]
else:
indentation = len(lines[1]) - len(lines[1].lstrip())
return '\n'.join([lines[0]] + [line[indentation:] for line in lines[1:]])
Demo:
def some_decorator(x):
return x
@some_decorator
def foo():
print("bar")
def func():
def inner(a, b='a:b'):
print (100)
a = c + d
print ('woof!')
def inner_inner():
print (200)
print ('spam!')
return inner
def func_one_liner(): print (200); print (a, b, c)
async def async_func_one_liner(): print (200); print (a, b, c)
def multi_line_1(
a=10,
b=100): print (100); print (200)
def multi_line_2(
a=10,
b=100
): print (100); print (200)
def multi_line_3(
a=10,
b=100
):
print (100 + '\n')
print (200)
async def multi_line_4(
a=10,
b=100
):
print (100 + '\n')
print (200)
async def multi_line_5(
a=10,
b=100
): print (100); print (200)
def func_annotate(
a: 'x', b: 5 + 6, c: list
) -> max(2, 9): print (100); print (200)
print (get_function_body(foo))
print (get_function_body(func()))
print (get_function_body(func_one_liner))
print (get_function_body(async_func_one_liner))
func_one_liner = some_decorator(func_one_liner)
print (get_function_body(func_one_liner))
@some_decorator
@some_decorator
def foo():
print("bar")
print (get_function_body(foo))
print (get_function_body(multi_line_1))
print (get_function_body(multi_line_2))
print (get_function_body(multi_line_3))
print (get_function_body(multi_line_4))
print (get_function_body(multi_line_5))
print (get_function_body(func_annotate))
Output:
foo's body:
print("bar")
inner's body:
print (100)
a = c + d
print ('woof!')
def inner_inner():
print (200)
print ('spam!')
func_one_liner's body:
print (200); print (a, b, c)
async_func_one_liner's body:
print (200); print (a, b, c)
func_one_liner's body:
print (200); print (a, b, c)
foo's body:
print("bar")
multi_line_1's body:
print (100); print (200)
multi_line_2's body:
print (100); print (200)
multi_line_3's body:
print (100 + '\n')
print (200)
multi_line_4's body:
print (100 + '\n')
print (200)
multi_line_5's body:
print (100); print (200)
func_annotate's body:
print (100); print (200)
Answered By – Ashwini Chaudhary
Answer Checked By – Jay B. (BugsFixing Admin)