Python Basics for Beginners: Data Structures, Loops, Functions, NumPy, Pandas, Matplotlib & Seaborn

Python Basics: Complete Guide for Beginners

Python is one of the most popular and beginner-friendly programming languages. Its simple syntax, vast libraries, and versatility make it ideal for web development, data analysis, artificial intelligence, automation, and more.

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🚀 Python Basics

Python is an interpreted, high-level, and general-purpose programming language. It emphasizes readability and reduces the cost of program maintenance.

👉 Key Features of Python:

• Easy to learn and read
• Open-source with vast community support
• Extensive libraries and frameworks
• Supports multiple programming paradigms (Procedural, Object-Oriented, Functional)

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📦 Python Data Structures

Data structures are fundamental concepts in programming used to store and organize data efficiently.

1. Lists

• Ordered, mutable collections.
• Can store mixed data types.

fruits = ['apple', 'banana', 'cherry']

2. Tuples

• Ordered, immutable collections.

coordinates = (10, 20)

3. Sets

• Unordered, mutable, no duplicate elements.

unique_numbers = {1, 2, 3}

4. Dictionaries

• Key-value pairs, unordered, mutable.

student = {'name': 'John', 'age': 21}

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⚙️ Python Programming Fundamentals

✅ Variables & Data Types

• Numbers: int, float, complex
• Strings: Text data
• Booleans: True or False

✅ Operators

• Arithmetic: +, -, *, /, %, **
• Comparison: ==, !=, >, <, >=, <=
• Logical: and, or, not

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🔀 Conditions and Branching

Used to make decisions in code.

age = 18
if age >= 18:
    print("You are an adult")
else:
    print("You are a minor")

👉 Conditional Statements:

• if
• if...else
• if...elif...else

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🔁 Loops in Python

✅ For Loop

for i in range(5):
    print(i)

✅ While Loop

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

✅ Loop Control Statements:

• break – exits the loop
• continue – skips the current iteration
• pass – does nothing (placeholder)

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🧠 Functions in Python

✅ Defining a Function:

def greet():
    print("Hello, Welcome!")

✅ Function with Arguments:

def greet(name):
    print("Hello", name)

✅ Return Statement:

def add(a, b):
    return a + b

✅ Types of Functions:

• Built-in Functions (e.g., len(), print(), type())
• User-defined Functions

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📦 Python Packages

✅ Importing a Package:

import math
print(math.sqrt(16))

✅ Popular Python Libraries:

• NumPy – Numerical computations
• Pandas – Data manipulation
• Matplotlib – Data visualization
• Seaborn – Advanced visualization

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🔢 Working with NumPy

✅ Installing NumPy:

pip install numpy

✅ Basic Operations:

import numpy as np
arr = np.array([1, 2, 3, 4])
print(arr)

✅ Array Operations:

• Mathematical: sum, mean, max, min
• Array slicing and reshaping

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📊 Working with Pandas

✅ Installing Pandas:

pip install pandas

✅ Creating DataFrames:

import pandas as pd
data = {'Name': ['John', 'Alice'], 'Age': [25, 30]}
df = pd.DataFrame(data)
print(df)

✅ Data Operations:

• Reading: read_csv(), read_excel()
• Viewing: head(), info(), describe()
• Manipulating: drop(), fillna(), groupby()

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📈 Introduction to Data Visualization

Data visualization transforms data into graphical representations, making insights easier to understand.

✅ Popular Python Visualization Libraries:

• Matplotlib – Basic plotting
• Seaborn – Statistical graphics

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📊 Introduction to Matplotlib and Seaborn

1. Matplotlib

Matplotlib is a basic plotting library.

import matplotlib.pyplot as plt

x = [1, 2, 3, 4]
y = [10, 20, 30, 40]

plt.plot(x, y)
plt.title('Line Chart')
plt.xlabel('X Axis')
plt.ylabel('Y Axis')
plt.show()

2. Seaborn

Seaborn is built on top of Matplotlib and offers advanced visualization.

import seaborn as sns
import pandas as pd

data = {'Age': [22, 25, 30, 35], 'Salary': [30000, 50000, 60000, 80000]}
df = pd.DataFrame(data)

sns.barplot(x='Age', y='Salary', data=df)

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📌 Conclusion

Python is a versatile language offering tools for data analysis, machine learning, web development, and more. Mastering Python basics, data structures, control flow, functions, and libraries like NumPy, Pandas, Matplotlib, and Seaborn sets a strong foundation for anyone stepping into the programming world.