A Reference Guide to Commonly Used Python Commands

Python, a widely popular programming language, offers a robust set of commands that empower developers to build a diverse range of applications. In this article, we provide a reference guide to some of the most commonly used Python commands, categorizing them based on their functionality.

1. Basic Commands

• print(): Used to display output on the console.

pythonprint("Hello, World!")


input(): Reads user input from the console.

pythonuser_input = input("Enter your name: ")
print("Hello, " + user_input + "!")

2. Data Types and Variables

Python supports various data types such as integers, floats, strings, lists, tuples, dictionaries, and sets.

python# Integer
x = 10
# Float
y = 3.14
# String
name = "Alice"
# List
my_list = [1, 2, 3, 4]
# Tuple
my_tuple = (1, 2, 3, 4)
# Dictionary
my_dict = {"name": "Alice", "age": 30}

3. Control Flow Statements

if, elif, else: Used for conditional statements.

pythonif x > 5:
    print("x is greater than 5")
elif x == 5:
    print("x is equal to 5")
else:
    print("x is less than 5")


for: Iterates over sequences.

pythonfor i in range(5):
    print(i)


while: Executes a block repeatedly based on a condition.

pythoncount = 0
while count < 5:
    print(count)
    count += 1

4. Functions

def: Used to define a new function.

pythondef greet(name):
    return "Hello, " + name + "!"

print(greet("Alice"))

5. Lists and Dictionaries

Python offers a wide range of methods for manipulating lists and dictionaries.

python# List methods
my_list.append(5)  # Add an item to the end
my_list.pop()  # Remove and return the last item

# Dictionary methods
my_dict["address"] = "123 Street"  # Add a new key-value pair
del my_dict["age"]  # Delete a key-value pair

6. File Operations

Python provides various commands for reading, writing, and manipulating files.

python# Open a file for writing
with open("file.txt", "w") as f:
    f.write("Hello, World!")

# Open a file for reading
with open("file.txt", "r") as f:
    print(f.read())

7. Modules and Packages

Python has a vast library of modules and packages that provide additional functionality.

python# Import a module
import math
print(math.sqrt(16))

# Import a specific function from a module
from math import sqrt
print(sqrt(16))

8. Exception Handling

Python offers try, except, and finally blocks for handling errors and exceptions gracefully.

pythontry:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero!")

Conclusion
This reference guide provides an overview of some of the most commonly used Python commands. While this list is not exhaustive, it covers the fundamental commands that form the basis of Python programming. With further exploration and practice, you’ll discover even more commands and techniques that can enhance your Python programming skills.