Return to Answer

def sanitised_input(prompt, type_=None, min_=None, max_=None, range_=None):
 if min_ is not None and max_ is not None and max_ < min_:
 raise ValueError("min_ must be less than or equal to max_.")
 while True:
 ui = input(prompt)
 if type_ is not None:
 try:
 ui = type_(ui)
 except ValueError:
 print("Input type must be {0}.".format(type_.__name__))
 continue
 if max_ is not None and ui > max_:
 print("Input must be less than or equal to {0}.".format(max_))
 elif min_ is not None and ui < min_:
 print("Input must be greater than or equal to {0}.".format(min_))
 elif range_ is not None and ui not in range_:
 if isinstance(range_, range):
 template = "Input must be between {0.start} and {0.stop}."
 print(template.format(range_))
 else:
 template = "Input must be {0}."
 if len(range_) == 1:
 print(template.format(*range_))
 else:
 print(template.format(" or ".join((", ".join(map(str,
 range_[:-1])),
 str(range_[-1])))))
 else:
 return ui

def sanitised_input(prompt, type_=None, min_=None, max_=None, range_=None):
 if min_ is not None and max_ is not None and max_ < min_:
 raise ValueError("min_ must be less than or equal to max_.")
 while True:
 ui = input(prompt)
 if type_ is not None:
 try:
 ui = type_(ui)
 except ValueError:
 print("Input type must be {0}.".format(type_.__name__))
 continue
 if max_ is not None and ui > max_:
 print("Input must be less than or equal to {0}.".format(max_))
 elif min_ is not None and ui < min_:
 print("Input must be greater than or equal to {0}.".format(min_))
 elif range_ is not None and ui not in range_:
 if isinstance(range_, range):
 template = "Input must be between {0.start} and {0.stop}."
 print(template.format(range_))
 else:
 template = "Input must be {0}."
 if len(range_) == 1:
 print(template.format(*range_))
 else:
 expected = " or ".join((
 ", ".join(str(x) for x in range_[:-1]),
 str(range_[-1])
 ))
 print(template.format(expected))
 else:
 return ui

The simplest way to accomplish this would be to put the input method in a while loop. Use continue when you get bad input, and break out of the loop when you're satisfied.

The simplest way to accomplish this is to put the input method in a while loop. Use continue when you get bad input, and break out of the loop when you're satisfied.

Use try and catch to detect when the user enters data that can't be parsed.

Use try and except to detect when the user enters data that can't be parsed.