Basics of Python 02: Control Structures
Control Structures in Python
In this section of the tutorial, we will delve into the core control structures of Python programming: Conditional Statements and Loops. Understanding these concepts is crucial as they control the flow of execution in a program.
1.1 Conditional Statements (if, elif, else)
Conditional statements are used to execute code only if a certain condition is met. Here’s how to use them:
if condition:
# code to execute if condition is True
elif another_condition:
# code to execute if another_condition is True
else:
# code to execute if none of the above conditions are True
Example:
age = 20
if age < 18:
print("You are a minor.")
elif age == 18:
print("Congratulations! You are 18.")
else:
print("You are an adult.")
1.2 Loops (for, while)
Loops are used to execute a block of code repeatedly.
1.2.1 The for Loop
The for loop is used to iterate over a sequence (list, tuple, string, or range).
for variable in sequence:
# code to execute for each item in sequence
Example:
fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
print(fruit)
1.2.2 The while Loop
The while loop repeats as long as a certain boolean condition is met.
while condition:
# code to execute while condition is True
Example:
count = 0
while count < 5:
print(count)
count += 1
1.3 Loop Control Statements (break, continue, pass)
1.3.1 break
The break statement is used to exit the loop prematurely when a certain condition is met.
Example:
for i in range(10):
if i == 5:
break
print(i)
1.3.2 continue
The continue statement skips the rest of the code inside the loop for the current iteration.
Example:
for i in range(10):
if i % 2 == 0:
continue
print(i)
1.3.3 pass
The pass statement is a null operation; nothing happens when it executes. It is used as a placeholder.
Example:
for i in range(10):
if i % 2 == 0:
pass
else:
print(i)
With these control structures, you can start building more complex and interesting programs in Python. Practice using these concepts to get comfortable with them. Happy coding!
