🔍 Regular Expressions

import re

text = "Python 3.12 released in 2024!"

# Search — pehla match dhundo
m = re.search(r'\d+', text)
print(m.group())  # 3

# findall — sab matches
nums = re.findall(r'\d+', text)
print(nums)  # ['3', '12', '2024']

# match — starting se check
m2 = re.match(r'Python', text)
print(m2.group())  # Python

import re

# Email validate
email = "rahul@gmail.com"
pattern = r'[a-zA-Z0-9.]+@[a-zA-Z0-9.]+\.[a-zA-Z]{2,}'
print(bool(re.match(pattern, email)))  # True

# Phone validate
phone = "9876543210"
print(bool(re.match(r'[6-9]\d{9}', phone)))  # True

# Replace
t = "Hello   World"
clean = re.sub(r'\s+', ' ', t)
print(clean)  # Hello World

import re

# split — multiple separators se
text = "one,two;three.four"
words = re.split(r'[,;.]', text)
print(words)  # ['one','two','three','four']

# sub — replace
text2 = "2026-03-13"
new   = re.sub(r'-(\d+)-', r'/\1/', text2)
print(new)    # 2026/03/13

# Extract numbers
prices = "Shirt ₹500, Pants ₹1200, Shoes ₹2000"
amts = re.findall(r'\d+', prices)
print(f"Total: ₹{sum(map(int, amts))}")

# Chapter 19: Regex — Advanced Practice
print("=== Regex Practice ===")

# Example 1: Basic usage
result = "Python mein Regex bahut powerful hai!"
print(result)

# Example 2: Real world use
data = ["Regex", "Python", "Hindi", "PythonHindi.in"]
for item in data:
    print(f"Item: {item}")

print("\nPractice complete! Great job! 🎉")

# Chapter 19: Regular Expressions — Advanced Examples
# Yeh code copy karo aur run karo!

# Example 1: Basic concept
print("=== Chapter 19: Regular Expressions ===")

# Example 2: List operations
items = ["Python", "Hindi", "Code", "Practice"]
for i, item in enumerate(items, 1):
    print(f"{i}. {item}")

# Example 3: Dictionary usage
chapter_info = {
    "number": 19,
    "title":  "Regular Expressions",
    "level":  "Intermediate",
    "done":   False
}
for key, value in chapter_info.items():
    print(f"  {key:10}: {value}")

# Example 4: Function
def practice_summary(chapter, completed=False):
    status = "Complete ✅" if completed else "In Progress ⏳"
    return f"Chapter {chapter}: {status}"

print(practice_summary(19))
print(practice_summary(19, True))