8 Input Validation

Question 1

1.What is an alternative to:
input()
2. Why is it useful?
3. How can you import it with a shorter name?

Answer 1

1. PyInputPlus
2. It allows pre-configured input validation, e.g. accepting only numbers and giving feedback if the criteria is not met
3. import pyinputplus as pyip

Question 2

What is the standard structure of the different pyInputPlus methods?
Name 3x prompt examples
Name 3x prompt parameters

Answer 2

Structure:
»>input*(‘message’, ‘parameter for specification’)

Prompts:
»>inputDate()
»>inputStr()
»>inputInt()

Specification:
»>inputInt(‘Enter your age: ‘, min=1)

Question 3

How can you display multiple options?
A. Selecting by value
B. Selecting by Number

Answer 3

A.
>>>response = 
pyip.inputMenu(['cat', 'dog', 'mouse'])
  * cat
  * dog
  * mouse
B. (['cat', 'dog', 'mouse'], numbered=True)
  1. cat
  2. dog
  3. mouse

Question 4

What command gives an overview over common input*() Parameters?

Answer 4

> > > help(pyip.paramters)

Question 5

How can you customize input validation?

Answer 5

By using a function and
>>>pyip.inputCustom(validFunc)
e.g.:
>>> def raiseIfUppercase(text):
...     if text.isupper():
...         raise Exception('Input cannot be uppercase.')
...
>>> inputCustom(raiseIfUppercase)

Question 6

How can you use a regex with pyip?

Make it so that everything Number is blocked, that ends with a 1, 3 or 5

What is the equivalent?

Answer 6

> > > response = pyip.inputNum(blockRegexes=[r’[135]$]’)

Equivalent:
allowRegexes=r[…]

Question 7

Name the 4 parameters that can be used with pyip.inputNum(‘message’, parameter)

Answer 7

parameter:
min=X
max=X
greaterThan=X
lessThan=Y

Question 8

Does pyip.input*() allow blank input?

Answer 8

The default is blank=False

Setting it to blank=True in the Parameter enables it.

Question 9

1. How can you change how often/ long the user is asked for input?
2. How do you change the return value if the input is wrong?

Answer 9

1. pyipInput(timeout=10)
   –> 10 seconds
   pyipInput(limit=2)
   –> 2 tries
2. pyipInput*(default=’message’)