Conditional statements in Python allow you to control the flow of your program based on certain conditions. These statements help you make decisions and execute specific blocks of code depending on whether a condition evaluates to True
or False
. The primary conditional statements in Python are if
, elif
(else if), and else
.
The if
Statement:
The if
statement is used to execute a block of code if a specified condition is true.
x = 10
if x > 5:
print("x is greater than 5")
In this example, the indented block of code under the if
statement will be executed only if the condition x > 5
evaluates to True
.
The if-else
Statement:
The if-else
statement allows you to specify two blocks of code: one to be executed if the condition is True
, and another if the condition is False
.
x = 3
if x > 5:
print("x is greater than 5")
else:
print("x is not greater than 5")
In this case, if x
is greater than 5, the first block of code will be executed; otherwise, the second block will be executed.
The if-elif-else
Statement:
The if-elif-else
statement is used when you have multiple conditions to check.
x = 5
if x > 5:
print("x is greater than 5")
elif x == 5:
print("x is equal to 5")
else:
print("x is less than 5")
Here, the code checks multiple conditions in order. If the first condition is True
, the corresponding block is executed. If not, it moves to the next condition (elif
). If none of the conditions is True
, the else
block is executed.
Nested if
Statements:
You can also have if
statements inside other if
statements, creating nested structures.
x = 10
if x > 5:
print("x is greater than 5")
if x > 8:
print("x is also greater than 8")
else:
print("x is not greater than 8")
else:
print("x is not greater than 5")
Nested if
statements allow you to handle more complex logic by checking multiple conditions in a hierarchical manner.
Ternary Conditional Operator:
Python supports a concise way to express conditional statements known as the ternary conditional operator.
x = 8
result = "greater than 5" if x > 5 else "less than or equal to 5"
print(result)
This is equivalent to the following if-else
statement:
if x > 5:
result = "greater than 5"
else:
result = "less than or equal to 5"
Understanding and effectively using conditional statements is crucial for writing flexible and responsive programs that can adapt to different scenarios and conditions.