Question: User: https://www.youtube.com/watch?v=rRTjPnVooxE
Explain while loops in Python with examples including input validation and logical operators.
## **While Loops in Python**
### **1. Introduction to While Loops**
- A while loop executes code repeatedly while a given condition is true.
- It is useful for repeated actions until a condition changes.
### **2. Simple Input Validation Example**
- Ask the user for their name:
name = input('Enter your name')
- If name is empty, print a warning; else greet the user.
- Using an if statement runs the check once.
### **3. Replacing If with While for Repeated Prompt**
- Use a while loop to keep asking for the name while it is empty:
while name == ''
- Inside the loop, re-prompt for the name.
- After exiting the loop, greet the user with print(f'Hello {name}').
- This prevents continuing until valid input is given.
### **4. Infinite Loop Warning**
- Without re-prompting inside the while loop, the condition never changes, causing an infinite loop.
- Always include an exit strategy like re-prompting user input inside the loop.
### **5. Example: Validating Age Input**
- Prompt for age and convert to integer:
age = int(input('Enter your age'))
- While age is less than zero:
while age < 0
- Print error message and re-prompt for age.
- After valid input, print age with print(f'You are {age} years old').
### **6. Using Logical Operators with While Loops**
- Example: Prompt for a food they like, quit on 'q'.
- Use while food.lower() != 'q' to continue until 'q' is pressed.
- Inside loop, print liked food and re-prompt.
- Print "bye" after loop ends.
### **7. Using OR Logical Operator for Range Validation**
- Prompt user for a number between 1 and 10:
num = int(input('Enter a number between 1 and 10'))
- While number is less than 1 or greater than 10:
while num < 1 or num > 10
- Print invalid message and re-prompt.
- After valid input, print the number.
### **8. Summary**
- While loops execute code while conditions are true.
- Useful for input validation and repeating tasks.
- Must include exit conditions to avoid infinite loops.
- Logical operators like not and or expand loop control.
- Essential tool for interactive programs in Python.