User Inputs, Control Statements, Loops

User Inputs

To take user inputs in Python, you can use the input() function. By default, input() returns a string, so you’ll need to convert it to the desired data type (int, float, or string) using int(), float(), or leave it as is.

Here’s an example code that takes user inputs in different data types:

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# Taking an integer input
user_input_int = int(input("Enter an integer: "))

# Taking a floating-point input
user_input_float = float(input("Enter a float: "))

# Taking a string input
user_input_string = input("Enter a string: ")

# Printing the inputs
print(f"You entered an integer: {user_input_int}")
print(f"You entered a float: {user_input_float}")
print(f"You entered a string: {user_input_string}")

In this example, int(input(...)) is used to take an integer input, float(input(...)) is used for a floating-point input, and input(...) alone is used for a string input.

Keep in mind that if the user provides input that cannot be converted to the specified data type, a ValueError will be raised. You might want to handle this using try-except blocks if necessary.

Control Statements

Certainly! Here are examples of if, else, elif, and nested if statements in Python:

if statement:

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# Example 1: Checking if a number is positive
num = 10

if num > 0:
    print("The number is positive.")

if-else statement:

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# Example 2: Checking if a number is even or odd
num = 7

if num % 2 == 0:
    print("The number is even.")
else:
    print("The number is odd.")

elif statement:

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# Example 3: Determining the grade based on a score
score = 75

if score >= 90:
    print("Grade A")
elif score >= 80:
    print("Grade B")
elif score >= 70:
    print("Grade C")
elif score >= 60:
    print("Grade D")
else:
    print("Grade F")

Nested if statements:

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# Example 4: Nested if statements to determine eligibility for a loan
income = 50000
credit_score = 700

if income >= 60000:
    if credit_score >= 700:
        print("You are eligible for a loan with a low interest rate.")
    else:
        print("You are eligible for a loan with a higher interest rate.")
else:
    print("You are not eligible for a loan.")

In the last example, we have a nested if statement. This means there is an if statement inside another if statement. The inner if statement is only executed if the condition of the outer if statement is true.

Remember, in Python, indentation is crucial. The code within a block is indented, and the standard convention is to use 4 spaces for each level of indentation.

These examples showcase the basic usage of conditional statements in Python. Depending on the condition(s) evaluated, different code blocks are executed.

Loops

1. For Loops:

  • Use for loops to iterate over a sequence (e.g., a list, tuple, or string).
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   fruits = ['apple', 'banana', 'cherry']
   for fruit in fruits:
       print(fruit)

2. While Loops:

  • Use while loops to repeatedly execute a block of code while a condition is True.
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   count = 0
   while count < 5:
       print(count)
       count += 1

3. Break and Continue:

  • Use break to exit a loop prematurely, and continue to skip the current iteration.
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   for i in range(10):
       if i == 5:
           break
       print(i)

   for i in range(10):
       if i == 5:
           continue
       print(i)

4. Looping through Dictionaries:

  • You can loop through the keys, values, or items of a dictionary.
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   person = {'name': 'John', 'age': 30, 'city': 'New York'}
   for key, value in person.items():
       print(f'{key}: {value}')

5. Loop Control with Else:

  • You can use an else block with a loop, which executes when the loop completes without hitting a break.
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   for i in range(5):
       print(i)
   else:
       print("Loop completed without a break.")

6. List Comprehensions:

  • A concise way to create lists.
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   numbers = [i for i in range(10) if i % 2 == 0]

These control structures and loops are powerful tools in Python that allow you to build complex programs and automate repetitive tasks. Practice using them in various scenarios to become proficient in controlling the flow of your code. Happy coding! 🚀

SAMPLE PROGRAM

Certainly! Below is a sample Python program that demonstrates user inputs, control statements (if-else), and loops (for loop and while loop):

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# User inputs
name = input("Enter your name: ")
age = int(input("Enter your age: "))

# Control statement (if-else)
if age >= 18:
    print(f"Hello {name}! You are eligible to vote.")
else:
    print(f"Hello {name}! You are not yet eligible to vote. You can vote in {18 - age} years.")

# For loop
print("Printing numbers from 1 to 5 using a for loop:")
for i in range(1, 6):
    print(i)

# While loop
num = int(input("Enter a number: "))
fact = 1
i = 1

while i <= num:
    fact *= i
    i += 1

print(f"The factorial of {num} is: {fact}")

This program does the following:

  1. Takes user inputs for name and age.
  2. Uses an if-else statement to check if the user is eligible to vote based on their age.
  3. Prints numbers from 1 to 5 using a for loop.
  4. Calculates the factorial of a number using a while loop.

Here’s an example of how the program would work:

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Enter your name: Alice
Enter your age: 22
Hello Alice! You are eligible to vote.
Printing numbers from 1 to 5 using a for loop:
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Enter a number: 5
The factorial of 5 is: 120

This program showcases the use of user inputs, control statements (if-else), and loops (for loop and while loop) in Python.