Decorators

Question

text = input()
def uppercase_decorator(func):
def wrapper(text):
print(text.upper())
return wrapper

@uppercase_decorator
def display_text(text):
return(text)

print(display_text(text))

Why in the end "None"

Answer 1

display_text(text) first calls the decorator function with function display_text as argument to it .

Decorator returns the wrapper function . After that wrapper function is called with the argument that is passed from display_text function to it.

wrapper function prints the uppercase value but doesn't returns anything . If it would have returned a value, using print(display_text(text)) would print that returned value but since no value is returned it prints None.

Edit:
The following is how the code works,

a=uppercase_decorator(display_text)
a(text) => prints uppercase value of text but since it returned nothing printing it out ( print(a(text)) ) will return None.