Input Statements

Imagine you're creating a program that asks a user for their favourite superhero. Now, that's where INPUT comes in! Here’s how we handle input in Python, starting with different types.

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Handling INPUT for Different Data Types

INTEGER Input

In pseudo-code:

DECLARE Age : INTEGER
OUTPUT "Enter your age:"
INPUT Age

Translated to Python:

Age = int(input("Enter your age: "))  # Converts input to an integer

Example:

print("Enter your age:")
Age = int(input())  # User enters 25
print("You are", Age, "years old!")

Result on screen:

Enter your age:
25
You are 25 years old!

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REAL Input

In pseudo-code:

DECLARE Price : REAL
OUTPUT "Enter the price of your favourite snack:"
INPUT Price

Translated to Python:

Price = float(input("Enter the price of your favourite snack: "))  # Converts input to a float

Example:

Price = float(input("Enter the price of your favourite snack: "))
print("Your snack costs £", Price)

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STRING Input

In pseudo-code:

DECLARE Name : STRING
OUTPUT "What's your name?"
INPUT Name

Translated to Python:

Name = input("What's your name? ")  # String input is the default

Example:

Name = input("What's your name? ")
print("Hello,", Name, "! Nice to meet you!")

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Array Inputs

1D Arrays

Let’s ask a user for a list of their favourite colours:

DECLARE Colours : ARRAY[1:5] OF STRING
OUTPUT "Enter your 5 favourite colours:"
FOR Counter ← 1 TO 5
    INPUT Colours[Counter]
NEXT Counter

Translated to Python:

Colours = []  # Initialising an empty list
print("Enter your 5 favourite colours:")
for Counter in range(5):
    Colours.append(input(f"Colour {Counter + 1}: "))  # Append input to the list
print("Your favourite colours are:", Colours)

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2D Arrays

Imagine a class where students' grades are stored in a grid:

DECLARE Grades : ARRAY[1:2, 1:3] OF INTEGER
OUTPUT "Enter grades for 2 students (3 subjects each):"
FOR Row ← 1 TO 2
    FOR Col ← 1 TO 3
        INPUT Grades[Row, Col]
    NEXT Col
NEXT Row

Translated to Python:

Grades = [[0] * 3 for _ in range(2)]  # Create a 2x3 grid of zeros
print("Enter grades for 2 students (3 subjects each):")
for Row in range(2):
    for Col in range(3):
        Grades[Row][Col] = int(input(f"Student {Row + 1}, Subject {Col + 1}: "))
print("The grades are:", Grades)

Example output:

Enter grades for 2 students (3 subjects each):
Student 1, Subject 1: 85
Student 1, Subject 2: 90
Student 1, Subject 3: 88
Student 2, Subject 1: 92
Student 2, Subject 2: 80
Student 2, Subject 3: 85
The grades are: [[85, 90, 88], [92, 80, 85]]

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