Control flow in Python refers to the order in which statements are executed in a program. It dictates the flow of execution, determining which statements are executed under certain conditions. Python's control flow is primarily managed through:
Conditional Statements (if
, elif
, else
):
A conditional statement in programming is a construct that allows the execution of different code blocks based on the evaluation of a specified condition.
In Python, the primary conditional statements are if
, elif
(short for "else if"), and else
. Here's a breakdown of their usage:
x = 10
if x > 0:
print("Positive")
elif x < 0:
print("Negative")
else:
print("Zero")
- The if
statement is used to execute a block of code only if a specified condition evaluates to True
.elif
Statement:
- The elif
statement is used to check additional conditions if the previous if
or elif
conditions are not met.else
Statement:
- The else
statement is used to execute a block of code when none of the preceding if
or elif
conditions is true.
Looping Statements (for
, while
):
Enable the repetition of code blocks.
# For loop
for i in range(5):
print(i)
# While loop
count = 0
while count < 3:
print("Count:", count)
count += 1
Control Statements (break
, continue
, pass
):
break
: Exits the innermost loop.continue
: Skips the rest of the loop and continues with the next iteration.pass
: Placeholder statement with no effect.for i in range(5):
if i == 3:
break
print(i)
Function Calls:
Break down code into reusable blocks with functions.
def greet(name):
print("Hello, " + name + "!")
greet("Alice") # Output: Hello, Alice!
Additional Control Flow Tools:
By effectively using these control flow structures, you can create Python programs that are flexible, dynamic, and capable of handling various inputs and conditions.
Control flow helps in making decisions, repeating tasks, and managing program flow based on certain conditions. It enhances the flexibility and responsiveness of Python programs.