6. More Migration Guide: From Python to C

6.1 Common Syntax Differences 
 
 
 
 Feature 
 Python 
 C 
 
 
 
 
 Comments 
 # This is a comment 
 // This is a comment 
 
 
 Block Comments 
 """Multi-line""" 
 /* Multi-line */ 
 
 
 Code Blocks 
 Indentation 
 { } braces 
 
 
 Statement End 
 Line break 
 ; semicolon 
 
 
 Boolean Values 
 True , False 
 1 , 0 (or true , false with <stdbool.h> ) 
 
 
 
 6.2 Variable Declaration Migration 
 Python to C Translation Examples: 
 # Python
age = 25
height = 5.9
name = "Alice"
is_student = True
 
 // C
int age = 25;
float height = 5.9f;
char name[] = "Alice";
int is_student = 1; // or use bool with #include <stdbool.h>
 
 6.3 Function Definition Migration (We will learn more about this on the next module) 
 Python: 
 def calculate_area(length, width):
 return length * width

result = calculate_area(5, 3)
print(result)
 
 C: 
 #include <stdio.h>

// Function declaration (prototype)
int calculate_area(int length, int width);

int main() {
 int result = calculate_area(5, 3);
 printf("%d\n", result);
 return 0;
}

// Function definition
int calculate_area(int length, int width) {
 return length * width;
}
 
 6.4 Common Pitfalls for Python Programmers 
 
 
 Forgetting Semicolons: 
 int x = 5 // ERROR: Missing semicolon
int x = 5; // CORRECT
 
 
 
 Using = instead of == in conditions: 
 if (x = 5) { ... } // ERROR: Assignment, not comparison
if (x == 5) { ... } // CORRECT: Comparison
 
 
 
 Forgetting & in scanf(): 
 scanf("%d", x); // ERROR: Missing &
scanf("%d", &x); // CORRECT
 
 
 
 Array Index Out of Bounds: (We will learn more about this on the next module) 
 int arr[5];
arr[5] = 10; // ERROR: Index 5 is out of bounds (valid: 0-4)
arr[4] = 10; // CORRECT: Last valid index