Advanced Conditionals
Ternary operators, match-case, chained comparisons, and conditional patterns.
Overview
Master advanced conditional patterns.
Ternary Operator
python
# Basic syntax
x = 10
result = "positive" if x > 0 else "non-positive"
print(result) # positive
# Nested ternary
x = 15
result = "positive" if x > 0 else "zero" if x == 0 else "negative"
print(result) # positive
# In function calls
def greet(name):
return f"Hello, {'friend' if not name else name}!"
print(greet("")) # Hello, friend!
print(greet("Alice")) # Hello, Alice!
Chained Comparisons
python
x = 15
# Multiple conditions
if 10 < x < 20:
print("x is between 10 and 20")
# Equivalent to
if 10 < x and x < 20:
print("x is between 10 and 20")
# Range check
age = 25
if 18 <= age <= 65:
print("Working age")
# Multiple equality
a = b = c = 5
if a == b == c:
print("All equal")
Match-Case (Python 3.10+)
python
# Basic match
def get_status(code):
match code:
case 200:
return "OK"
case 404:
return "Not Found"
case 500:
return "Server Error"
case _:
return "Unknown"
print(get_status(200)) # OK
# Pattern matching with OR
match command:
case "quit" | "exit" | "q":
print("Exiting...")
case "help" | "h":
print("Showing help...")
case _:
print("Unknown command")
# Matching with capture
match point:
case (0, 0):
print("Origin")
case (x, 0):
print(f"On x-axis at {x}")
case (0, y):
print(f"On y-axis at {y}")
case (x, y):
print(f"Point at ({x}, {y})")
# Class matching
match event:
case Click(position=(x, y)):
handle_click(x, y)
case KeyPress(key_name="Q"):
quit()
case KeyPress(key_name=key):
handle_key(key)
Conditional Patterns
python
# Guard clauses
def process_data(data):
if not data:
return None
if not isinstance(data, list):
return None
if len(data) == 0:
return None
return [x * 2 for x in data]
# Dictionary dispatch
def handle_action(action, value):
actions = {
"add": lambda x: x + 1,
"subtract": lambda x: x - 1,
"multiply": lambda x: x * 2,
}
handler = actions.get(action)
if handler:
return handler(value)
return None
Practice
Implement a calculator using match-case.