Python ยท Chapter 12 of 45
Python If / Else
The `if` statement runs a block only when a condition is true. Add `elif` for extra conditions and `else` as a catch-all.
Remember: colon at the end of the line, and indent the body.
Syntax
if condition:
...
elif other:
...
else:
...Basic structure
if / elif / else evaluates from top to bottom and runs the FIRST true branch.
Ternary expression
`value = a if condition else b` is a compact if/else that produces a value.
Example 1 (python)
age = 18
if age >= 18:
print("Adult")
else:
print("Minor")Output
AdultThe if branch runs because 18 >= 18.
Example 2 (python)
score = 72
grade = "Pass" if score >= 40 else "Fail"
print(grade)Output
PassTernary expression assigns 'Pass' or 'Fail' in one line.
Key points
- End the if/elif/else line with a colon.
- Indent the body (4 spaces).
- First matching branch wins.
- Use `elif`, not `else if`.
๐ก Note: Python has no switch/case in older versions; `match` was added in Python 3.10 for pattern matching.