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Conditions and Branching

July 24, 2025 3 min read Data-Science Control-Flow Docs IBM-FSSD Branching Logic

This document explains Python conditions and branching, including comparison operators, Boolean logic, if/else/elif statements, and practical examples for decision-making in code.

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This document covers Python conditions and branching, including comparison operators, Boolean logic, if/else/elif statements, and practical examples for decision-making in code.

Introduction

Conditions and branching in Python allow programs to make decisions based on comparisons and logical operations. These features are essential for controlling program flow.

Comparison Operators

Comparison operations compare values and produce Boolean results:

OperatorDescriptionExampleResult
==Equal to6 == 7False
!=Not equal to2 != 6True
>Greater than6 > 5True
<Less than2 < 6True
>=Greater or equal5 >= 5True
<=Less or equal2 <= 5True

Comparison can be applied to numbers and strings.

Branching with if, else, and elif

Branching enables different code execution based on conditions.

if Statement

Executes code if the condition is true:

1age = 19
2if age >= 18:
3    print("You will enter")
4print("Move on")

else Statement

Executes code if the condition is false:

1age = 17
2if age >= 18:
3    print("You will enter")
4else:
5    print("Go see Meatloaf")
6print("Move on")

elif Statement

Checks additional conditions if previous ones are false:

1age = 18
2if age > 18:
3    print("You can enter")
4elif age == 18:
5    print("Go see Pink Floyd")
6else:
7    print("Go see Meatloaf")
8print("Move on")

Logical Operators

Logical operators combine Boolean values:

OperatorDescriptionExampleResult
notNegationnot TrueFalse
orEitherTrue or FalseTrue
andBothTrue and FalseFalse

Logical operators are used to build complex conditions.

Practical Examples

  • Use comparison operators to compare numbers and strings.
  • Use if, else, and elif statements to control program flow based on conditions.
  • Use logical operators to combine multiple conditions.

Conclusion

Conditions and branching are fundamental for decision-making in Python. Mastering comparison and logical operators, along with branching statements, enables flexible and intelligent program control.

FAQ

Comparison operators compare values and produce Boolean results, enabling decision-making in code.

The code block under the if statement is skipped, and execution continues with the next statement or the else/elif block if present.

  1. not
  2. or
  3. and
  4. xor
(4) Python does not have a built-in xor logical operator; use combinations of not, or, and and instead.

The elif statement checks an additional condition if the previous if condition is false, allowing for multiple decision branches.

ConceptDescription
A. if1. Executes code if condition is true
B. else2. Executes code if all previous conditions are false
C. elif3. Checks additional condition if previous is false
D. not4. Negates a Boolean value
A-1, B-2, C-3, D-4.

Logical operators can be used to combine multiple conditions in Python branching statements.

True. Logical operators like and, or, and not allow combining multiple conditions.

Ensure the strings are in the correct format and case, as comparisons are case-sensitive.

The != operator checks if two values are not equal.

Branching enables programs to execute different code paths based on conditions, improving flexibility and control.

The and operator requires all combined conditions to be true for the code block to execute.
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