Determine if variable is defined or not

Determine if variable is defined or not.

try:
  x = 1
except NameError:
  print("Variable is not defined....!")
else:
  print("Variable is defined.")

try:
  y
except NameError:
  print("Variable is not defined....!")
else:
  print("Variable is defined.")

Output:

Variable is defined.
Variable is not defined....!

See also

https://www.w3resource.com/python-exercises/python-basic-exercise-121.php