Conditional with statement in Python

Question

Is there a way to begin a block of code with a with statement, but conditionally?

Something like:

if needs_with():
    with get_stuff() as gs:

# do          


        

Answer 1

I have found that the @Anentropic answer is incomplete.

from conditional import conditional

a = 1 # can be None

if not a is None:
  b = 1

class WithNone:
  def __enter__(self):
    return self
  def __exit__(self, type, value, tb):
    pass

def foo(x):
  print(x)
  return WithNone()

with conditional(not a is None, foo(b) if not a is None else None):
  print(123)

The complete conditional usage required 3 conditions instead of 1 because of:

1. NameError: name 'b' is not defined in case if not defined a
2. the function foo still must return enterable object, otherwise: AttributeError: 'NoneType' object has no attribute '__enter__'