# file run karne ke liye
python3 script.py

# interactive shell
python3
>>> print("Hello, Python!")

# Ye single line comment hai

"""
Ye multi-line comment
ya docstring hai
"""
print("Comments samajh aa gaye!")

x = 10          # int
y = 3.14        # float
z = "hello"     # str
flag = True     # bool
n = None        # NoneType
lst = [1, 2, 3] # list
tup = (1, 2)    # tuple
d = {"a": 1}    # dict
s = {1, 2, 3}   # set

print(type(x))   # data type check karne ke liye
print(x, y, z, flag, n, lst, tup, d, s)

name = "Amit"          # normal assignment
a, b, c = 1, 2, 3       # multiple assignment
x = y = z = 0            # same value multiple variables ko

a, b = b, a               # values swap karna
print(name, a, b, c, x, y, z)

count = 5
count += 1                 # count = count + 1 ke barabar
print(count)

s = "Namaste Python"

print(s.upper())          # NAMASTE PYTHON
print(s.lower())          # namaste python
print(s.strip())          # extra spaces hata deta hai
print(s.split(" "))       # list me todta hai
print(s.replace("a","o"))   # replace karta hai
print(len(s))              # length

# f-string (formatting)
name = "Riya"
print(f"Mera naam {name} hai")

# slicing
print(s[0:5])     # start se 5 index tak
print(s[::-1])    # string reverse

a = 10
b = 3

print(a + b)   # addition
print(a - b)   # subtraction
print(a * b)   # multiplication
print(a / b)   # division (float result)
print(a // b)  # floor division
print(a % b)   # modulus (remainder)
print(a ** b)  # power

import math
print(math.sqrt(16))
print(math.pi)
print(round(3.567, 2))

age = 20

if age >= 18:
    print("Aap adult hain")
elif age > 12:
    print("Aap teenager hain")
else:
    print("Aap bacche hain")

# ternary style
status = "Adult" if age >= 18 else "Minor"
print(status)

# for loop
for i in range(5):
    print(i)

# while loop
n = 0
while n < 5:
    print("while:", n)
    n += 1

# break aur continue
for i in range(10):
    if i == 5:
        break
    if i % 2 == 0:
        continue
    print("odd:", i)

def greet(name, msg="Namaste"):
    """Ye function greeting return karta hai"""
    return f"{msg}, {name}!"

print(greet("Amit"))

# *args aur **kwargs
def add_all(*args):
    return sum(args)

def show_info(**kwargs):
    for k, v in kwargs.items():
        print(k, v)

print(add_all(1, 2, 3, 4))
show_info(name="Riya", age=22)

# lambda function
square = lambda x: x * x
print(square(6))

class Student:
    def __init__(self, name, marks):
        self.name = name
        self.marks = marks

    def display(self):
        print(f"{self.name} ke marks: {self.marks}")

s1 = Student("Riya", 89)
s1.display()

# Inheritance
class TopStudent(Student):
    def __init__(self, name, marks, rank):
        super().__init__(name, marks)
        self.rank = rank

s2 = TopStudent("Aman", 95, 1)
s2.display()
print("Rank:", s2.rank)

try:
    result = 10 / 0
except ZeroDivisionError as e:
    print("Error:", e)
except Exception as e:
    print("Kuch aur error hua:", e)
else:
    print("Sab theek raha")
finally:
    print("Ye hamesha chalega")

# apna khud ka exception raise karna
try:
    raise ValueError("Galat value diya gaya hai")
except ValueError as e:
    print("Custom error pakda gaya:", e)

# List
fruits = ["apple", "mango", "banana"]
fruits.append("kiwi")
fruits.remove("mango")
fruits.sort()
print(fruits)

# Tuple (immutable)
point = (10, 20)
print(point)

# Dictionary
person = {"name": "Amit", "age": 25}
person["city"] = "Delhi"
print(list(person.keys()))
print(list(person.values()))
print(list(person.items()))

# Set
nums = {1, 2, 3}
nums.add(4)
print(nums)

# List comprehension
squares = [x*x for x in range(10)]
print(squares)

# Condition ke saath
even = [x for x in range(20) if x % 2 == 0]
print(even)

# Dictionary comprehension
d = {x: x*x for x in range(5)}
print(d)

# Set comprehension
s = {x*2 for x in range(5)}
print(s)

# File likhna
with open("data.txt", "w") as f:
    f.write("Namaste duniya")

# File padhna
with open("data.txt", "r") as f:
    content = f.read()
    print(content)

# line by line padhna (yahan ek hi line hai)
with open("data.txt", "r") as f:
    for line in f:
        print(line.strip())

import math
from datetime import datetime

print(math.factorial(5))
print(datetime.now().year)

# apna khud ka module banana:
# mymodule.py file banayein aur us me function likhein, phir:
# import mymodule
# mymodule.my_function()

# venv banana
python3 -m venv myenv

# activate karna (Windows)
myenv\Scripts\activate

# activate karna (Mac/Linux)
source myenv/bin/activate

# deactivate karna
deactivate

pip install requests
pip install pandas numpy

pip list                  # installed packages dekhna
pip uninstall requests

pip freeze > requirements.txt
pip install -r requirements.txt

print(len("Python"))     # length
print(type(10))            # data type
x = 5
print(id(x))                 # memory address
print(isinstance(x, int))    # type check

# multiple values ek line me print
print("A", "B", "C", sep=", ")