f strings if.elif

The introduction of f-strings in Python 3.6 has made string formatting more readable and concise. In this article, we'll explore how to combine f-strings with conditional statements to create dynamic strings based on variable values. Let's dive in!

Using f-strings with Conditional Statements in Python

Basic Understanding

F-strings, also known as formatted string literals, allow for embedding expressions inside string literals, using {}. When combined with conditional statements, they offer a compact way to embed logic directly within a string.

Examples

1. Basic if/else with a Single Variable:

   
   x = 1
   message = f"The number is {'greater than zero' if x > 0 else 'not greater than zero'}."
   print(message)
               

2. Using if/elif/else with a Single Variable:

   
   y = 0
   message = (
       f"The number is positive." if y > 0 else 
       f"The number is negative." if y < 0 else 
       f"The number is zero."
   )
   print(message)
               

3. Using Nested Conditional Expressions:

   
   age = 35
   is_student = True
   message = (
       f"Discount applied: Senior citizen." if age > 65 else 
       f"Discount applied: Student." if is_student else 
       f"No discount applied."
   )
   print(message)
               

4. Multiple Variables in Conditions:

   
   weight = 75
   height = 1.7
   bmi = weight / (height ** 2)
   category = (
       f"You are underweight." if bmi < 18.5 else 
       f"You are normal weight." if 18.5 <= bmi < 24.9 else 
       f"You are overweight." if 24.9 <= bmi < 30 else 
       f"You are obese."
   )
   print(f"Your BMI is {bmi:.2f}. {category}")
               

5. Complex Logic with List Comprehension:

   
   grades = [85, 92, 78, 63, 88, 90]
   messages = [
       f"Student {index + 1}: "
       f"{'Excellent' if grade > 90 else 'Good' if grade > 80 else 'Average' if grade > 70 else 'Poor'}"
       for index, grade in enumerate(grades)
   ]
   for message in messages:
       print(message)
               

Additional Practice

For those eager to further hone their skills, here are five additional practice examples:

1. Format a string to display whether a number is even or odd.
2. Use a variable representing a day of the week to display whether it's a weekday or a weekend.
3. Based on a student's age, determine and display which grade they're in (e.g., Kindergarten, 1st grade, etc.).
4. Given a temperature in Celsius, classify it as cold (< 10°C), moderate (10-25°C), or hot (> 25°C).
5. For a given month (e.g., "January"), display which season it falls under.

Documenting my journey as I enhance my Python skills. Stay tuned for more insights and tips! Google Colab Example