if
Resources
- Conditional statements in Real Python.
- if statement in the official documentation.
- Control flow in wikipedia.
if
if is one of the basic control flow statements. It allows us to execute some code only if a given condition is met.
If the condition is not met the code inside the if block won’t be executed.
Every line included in the block will be executed, not just the first one.
Fix the following code to print “Done!” even when the condition is not met.
Remember that a block ends when the indentation returns to the previous level.
Fix the following code.
else
It is common that we want to execute some code when the condition is met, and some other code when the condition is not met, for that we use else.
Fix this code:
Write some code capable of, given a pair of numbers, finding out which is the highest.
Fix the following code to prevent the error when a = 0.
elif
elif allows us to test for different conditions sequentialy.
When several conditions are met only the first True one will be executed.
In Python, a more powerful alternative to elif is the match statement.
Write a program that classifies a person into: baby, child, teenager, young, and old
Write a program that writes the quote of the selected philosopher.
Boolean casting
When a condition is evaluated, internally the if statement casts anything given to a boolean. So, you will usually see expressions like:
It would be very weird to write:
Remember that everything that we talked about booleans and boolean arithmetic is applicable to the if evaluation.