Python for Beginners: 15-Day Complete Learning Plan

Why Python?

Python is the #1 language for beginners and data scientists worldwide.

✅ Simple, English-like syntax
✅ Huge library ecosystem (pip install anything)
✅ Used in Web, ML, Data Science, Automation, Scripting
✅ Top choice for B.Tech placements (after DSA)
✅ Jupyter Notebooks for data science

Installation:

1. Download from python.org (Python 3.11+)
2. Install VS Code + Python extension
3. Verify: python --version in terminal

---

Day 1–3: Syntax & Basics

Variables & Data Types

# Python mein type declare karna zaruri nahi
name = "Rahul"           # str
age = 21                  # int
cgpa = 8.5               # float
is_placed = True          # bool
nothing = None            # None type

# Type check
print(type(name))         # <class 'str'>

# Multiple assignment
x = y = z = 0
a, b, c = 1, 2, 3        # Tuple unpacking

Input & Output

name = input("Enter your name: ")   # Always returns string
age = int(input("Enter age: "))      # Convert to int

# f-strings (Python 3.6+) — best way to format
print(f"Hello {name}, you are {age} years old!")

# Older style
print("Hello %s, age %d" % (name, age))
print("CGPA: {:.2f}".format(8.567))  # 8.57

Operators

# Arithmetic
10 + 3 = 13   | 10 - 3 = 7   | 10 * 3 = 30
10 / 3 = 3.33 | 10 // 3 = 3  | 10 % 3 = 1  | 2**10 = 1024

# Comparison → returns bool
x == y  |  x != y  |  x > y  |  x >= y

# Logical
True and False  → False
True or False   → True
not True        → False

# Python-specific
5 in [1,2,3,5]  → True
x is None       → True (identity check)

---

Day 4–6: Control Flow

Conditionals

marks = 75

if marks >= 90:
    grade = "A"
elif marks >= 75:
    grade = "B"
elif marks >= 60:
    grade = "C"
else:
    grade = "F"

# One-liner (ternary)
status = "Pass" if marks >= 40 else "Fail"

Loops

# for loop
for i in range(5):          # 0,1,2,3,4
    print(i)

for i in range(1, 11, 2):   # 1,3,5,7,9 (step=2)
    print(i)

# Iterate over list
fruits = ["apple", "banana", "mango"]
for fruit in fruits:
    print(fruit)

# enumerate — index + value
for i, fruit in enumerate(fruits):
    print(f"{i}: {fruit}")

# while loop
n = 1
while n <= 5:
    print(n)
    n += 1

# Loop control
break      # Exit loop
continue   # Skip to next iteration
pass       # Do nothing (placeholder)

List Comprehension (Python ka power feature!)

squares = [x**2 for x in range(10)]
# [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

evens = [x for x in range(20) if x % 2 == 0]
# [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]

# Nested
matrix = [[i*j for j in range(4)] for i in range(4)]

---

Day 7–9: Functions

# Basic function
def greet(name, greeting="Hello"):   # Default argument
    return f"{greeting}, {name}!"

print(greet("Priya"))              # Hello, Priya!
print(greet("Amit", "Namaste"))    # Namaste, Amit!

# Multiple return values
def min_max(nums):
    return min(nums), max(nums)

low, high = min_max([3, 1, 7, 2])

# *args — variable positional arguments
def sum_all(*args):
    return sum(args)

sum_all(1, 2, 3, 4, 5)  # 15

# **kwargs — variable keyword arguments
def show_info(**kwargs):
    for key, value in kwargs.items():
        print(f"{key}: {value}")

show_info(name="Rahul", college="IIT", cgpa=9.1)

# Lambda (anonymous function)
square = lambda x: x**2
double = lambda x, y: x + y
sorted_data = sorted(students, key=lambda s: s['cgpa'], reverse=True)

# Recursion
def factorial(n):
    if n <= 1:
        return 1
    return n * factorial(n-1)

factorial(5)  # 120

---

Day 10–12: Data Structures

List

nums = [3, 1, 4, 1, 5, 9, 2, 6]

nums.append(7)         # Add at end
nums.insert(0, 100)    # Insert at index 0
nums.remove(1)         # Remove first occurrence of 1
popped = nums.pop()    # Remove + return last
nums.sort()            # Sort in-place
nums.sort(reverse=True) # Descending
sorted_copy = sorted(nums)  # Returns new list

nums[0]    # First element
nums[-1]   # Last element
nums[1:4]  # Slice [1,4)
nums[::-1] # Reverse

len(nums), sum(nums), min(nums), max(nums)

Dictionary

student = {
    "name": "Priya",
    "rollno": 42,
    "cgpa": 8.9,
    "subjects": ["DSA", "OS", "DBMS"]
}

# Access
student["name"]                    # Priya
student.get("grade", "N/A")       # Default if not found

# Modify
student["cgpa"] = 9.1
student["college"] = "VIT"

# Iteration
for key in student:               # Keys only
    print(key)
for key, value in student.items(): # Key + value
    print(f"{key}: {value}")

# Dict comprehension
squares = {x: x**2 for x in range(6)}  # {0:0, 1:1, 2:4, ...}

Set & Tuple

# Set — unordered, unique elements
skills = {"Python", "SQL", "Git"}
skills.add("JavaScript")
skills.remove("Git")
set1 & set2   # Intersection
set1 | set2   # Union
set1 - set2   # Difference

# Tuple — immutable list
coords = (28.6, 77.2)   # lat, long — can't change
x, y = coords            # Unpack

Strings (Common Operations)

s = "Hello, World!"

s.upper()          # HELLO, WORLD!
s.lower()          # hello, world!
s.strip()          # Remove whitespace
s.split(",")       # ['Hello', ' World!']
s.replace("Hello", "Namaste")
s.startswith("Hello")  # True
s.find("World")    # 7 (index)
",".join(["a","b","c"])  # "a,b,c"
s[0:5]             # Hello
len(s)             # 13

---

Day 13: File Handling & Exception

# Write file
with open("notes.txt", "w") as f:
    f.write("First line\n")
    f.writelines(["Line 2\n", "Line 3\n"])

# Read file
with open("notes.txt", "r") as f:
    content = f.read()        # Entire file
    lines = f.readlines()     # List of lines

# Append mode
with open("notes.txt", "a") as f:
    f.write("New line\n")

# CSV with pandas
import pandas as pd
df = pd.read_csv("students.csv")
df.head(10)
df.to_csv("output.csv", index=False)

Exception Handling:

try:
    result = int(input("Enter number: "))
    print(10 / result)
except ValueError:
    print("Invalid number!")
except ZeroDivisionError:
    print("Can't divide by zero!")
except Exception as e:
    print(f"Error: {e}")
else:
    print("No error occurred")
finally:
    print("Always runs")

# Raise custom exception
def validate_age(age):
    if age < 0:
        raise ValueError(f"Age can't be negative: {age}")

---

Day 14: OOP (Object Oriented Programming)

class Student:
    university = "VIT"  # Class variable (shared)

    def __init__(self, name, rollno, cgpa):
        # Instance variables
        self.name = name
        self.rollno = rollno
        self.__cgpa = cgpa  # Private (name mangling)

    def get_cgpa(self):    # Getter
        return self.__cgpa

    def set_cgpa(self, cgpa):  # Setter
        if 0 <= cgpa <= 10:
            self.__cgpa = cgpa

    def introduce(self):
        return f"I'm {self.name}, Roll: {self.rollno}"

    def __str__(self):    # Called by print()
        return f"Student({self.name}, {self.rollno})"

    def __repr__(self):   # Developer representation
        return f"Student(name={self.name!r})"

# Inheritance
class TopStudent(Student):
    def __init__(self, name, rollno, cgpa, scholarship):
        super().__init__(name, rollno, cgpa)  # Call parent
        self.scholarship = scholarship

    def introduce(self):    # Override method
        base = super().introduce()
        return f"{base} — Scholarship: ₹{self.scholarship}"

# Usage
s1 = Student("Rahul", 42, 8.9)
s2 = TopStudent("Priya", 1, 9.8, 50000)

print(s1.introduce())
print(s2.introduce())
print(Student.university)  # Class variable

---

Day 15: 3 Mini Projects

Project 1: Student Grade Manager

students = {}

def add_student(name, marks):
    grade = "A" if marks>=90 else "B" if marks>=75 else "C" if marks>=60 else "F"
    students[name] = {"marks": marks, "grade": grade}

def show_all():
    for name, data in students.items():
        print(f"{name}: {data['marks']} → Grade {data['grade']}")

def top_student():
    return max(students, key=lambda n: students[n]['marks'])

add_student("Rahul", 88)
add_student("Priya", 95)
add_student("Amit", 72)
show_all()
print(f"Top student: {top_student()}")

Project 2: Simple To-Do List (with file save)

import json

FILENAME = "todos.json"

def load():
    try:
        with open(FILENAME) as f:
            return json.load(f)
    except FileNotFoundError:
        return []

def save(todos):
    with open(FILENAME, "w") as f:
        json.dump(todos, f, indent=2)

todos = load()

def add(task): todos.append({"task": task, "done": False}); save(todos)
def done(i): todos[i]["done"] = True; save(todos)
def show():
    for i, t in enumerate(todos):
        status = "✅" if t["done"] else "⬜"
        print(f"{i}. {status} {t['task']}")

Project 3: Number Guessing Game

import random

def play():
    target = random.randint(1, 100)
    attempts = 0
    print("Guess a number between 1 and 100!")
    
    while True:
        try:
            guess = int(input("Your guess: "))
            attempts += 1
            if guess < target:
                print("Too low! ⬇️")
            elif guess > target:
                print("Too high! ⬆️")
            else:
                print(f"🎉 Correct! You got it in {attempts} attempts!")
                break
        except ValueError:
            print("Please enter a valid number")

play()

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What's Next after 15 Days?

| Track | Topics | Libraries | |---|---|---| | Data Science | Numpy, Pandas, Matplotlib, EDA | pandas, matplotlib, seaborn | | Machine Learning | Regression, Classification, Clustering | scikit-learn, XGBoost | | Deep Learning | Neural Networks, CNNs, RNNs | TensorFlow, PyTorch | | Web Development | REST APIs, Databases | Flask, Django, FastAPI | | Automation | Web scraping, file automation | selenium, requests, BeautifulSoup | | DSA with Python | Solve LeetCode problems | heapq, collections, bisect |

Recommended Daily Practice: 2 hours theory + 30 min solving problems on LeetCode Easy