String Specifics

# Checking methods (return True/False)
print(f"islower(): {sample_text.islower()}")
print(f"isupper(): {sample_text.isupper()}")
print(f"isdigit(): {'123'.isdigit()}")
print(f"isalpha(): {'Hello'.isalpha()}")
print(f"isalnum(): {'Hello123'.isalnum()}")

# Search and count methods
print(f"count('o'): {sample_text.count('o')}")
print(f"count('Python'): {sample_text.count('Python')}")
print(f"find('World'): {sample_text.find('World')}")    # Returns index or -1
print(f"index('Python'): {sample_text.index('Python')}")  # Returns index or error

# startswith() and endswith()
print(f"startswith('Hello'): {sample_text.startswith('Hello')}")
print(f"endswith('Programming'): {sample_text.endswith('Programming')}")

# replace() method
original = "I like cats and cats like me"
replaced = original.replace("cats", "dogs")
print(f"Replace 'cats' with 'dogs': '{replaced}'")

# Replace with limit
limited_replace = original.replace("cats", "dogs", 1)  # Replace only first occurrence
print(f"Replace first 'cats' only: '{limited_replace}'")

# =============================================================================
# USING help(str) - Understanding Available Methods
# =============================================================================

print("\n--- Using help(str) ---")
print("To see all string methods, run: help(str)")
print("To see help for a specific method, run: help(str.methodname)")
print("Example: help(str.split)")
print("\nSome commonly used string methods:")

# Get all string methods (excluding private ones)
string_methods = [method for method in dir(str) if not method.startswith('_')]
print("Available string methods:")
for i, method in enumerate(string_methods, 1):
    print(f"  {method}", end="")
    if i % 6 == 0:  # New line every 6 methods
        print()
    else:
        print(", ", end="")
print()  # Final newline

# =============================================================================
# F-STRINGS - Modern String Formatting
# =============================================================================

print("\n--- F-String Formatting ---")

name = "Alice"
age = 30
height = 5.75
balance = 1234.56789

# Basic f-string usage
basic_f_string = f"My name is {name} and I am {age} years old."
print(f"Basic f-string: {basic_f_string}")

# Expressions inside f-strings
print(f"Next year I'll be {age + 1} years old.")
print(f"My name has {len(name)} letters.")
print(f"Am I an adult? {age >= 18}")

# Method calls inside f-strings
print(f"My name in uppercase: {name.upper()}")
print(f"My name reversed: {name[::-1]}")

# =============================================================================
# PRECISION FORMATTING IN F-STRINGS
# =============================================================================

print("\n--- Precision Formatting in F-Strings ---")

# Number formatting
pi = 3.14159265359
large_number = 1234567.89

# Decimal places
print(f"Pi to 2 decimal places: {pi:.2f}")
print(f"Pi to 4 decimal places: {pi:.4f}")
print(f"Large number to 1 decimal: {large_number:.1f}")

# Scientific notation
print(f"Pi in scientific notation: {pi:.2e}")
print(f"Large number in scientific: {large_number:.3e}")

# Percentage formatting
ratio = 0.856
print(f"Ratio as percentage: {ratio:.1%}")
print(f"Ratio as percentage (2 decimals): {ratio:.2%}")

# Width and alignment
print(f"Right aligned (width 10): '{pi:>10.2f}'")
print(f"Left aligned (width 10): '{pi:<10.2f}'")
print(f"Center aligned (width 10): '{pi:^10.2f}'")
print(f"Zero padded: '{pi:08.2f}'")

# Comma separators for large numbers
big_num = 1234567
print(f"With comma separators: {big_num:,}")
print(f"With comma and decimals: {big_num:,.2f}")

# String formatting
print(f"Name right aligned (width 15): '{name:>15}'")
print(f"Name left aligned (width 15): '{name:<15}'")
print(f"Name centered (width 15): '{name:^15}'")

# Date formatting (with datetime)
from datetime import datetime
now = datetime.now()
print(f"Current date: {now:%Y-%m-%d}")
print(f"Current time: {now:%H:%M:%S}")
print(f"Full datetime: {now:%Y-%m-%d %H:%M:%S}")

# =============================================================================
# PRACTICAL EXAMPLES
# =============================================================================

print("\n--- Practical Examples ---")

# Example 1: Processing user input
def process_name(full_name):
    """Clean and format a user's name"""
    # Strip whitespace and convert to title case
    cleaned = full_name.strip().title()
    
    # Split into parts
    parts = cleaned.split()
    
    if len(parts) >= 2:
        first_name = parts[0]
        last_name = parts[-1]
        return f"Hello, {first_name} {last_name}!"
    else:
        return f"Hello, {cleaned}!"

test_names = ["  john doe  ", "MARY SMITH", "bob"]
for name in test_names:
    result = process_name(name)
    print(f"'{name}' -> {result}")

# Example 2: Text analysis
def analyze_text(text):
    """Analyze text and return statistics"""
    # Clean the text
    cleaned = text.strip().lower()
    
    # Count different elements
    char_count = len(text)
    word_count = len(text.split())
    sentence_count = text.count('.') + text.count('!') + text.count('?')
    
    # Find most common letter
    letter_counts = {}
    for char in cleaned:
        if char.isalpha():
            letter_counts[char] = letter_counts.get(char, 0) + 1
    
    most_common = max(letter_counts, key=letter_counts.get) if letter_counts else 'N/A'
    
    return {
        'characters': char_count,
        'words': word_count,
        'sentences': sentence_count,
        'most_common_letter': most_common
    }

sample_text = "Python is amazing! It's powerful and easy to learn. I love coding with Python."
stats = analyze_text(sample_text)
print(f"\nText analysis for: '{sample_text}'")
for key, value in stats.items():
    print(f"  {key.replace('_', ' ').title()}: {value}")

# Example 3: Creating a formatted report
def create_report(students_grades):
    """Create a formatted grade report"""
    print("\n" + "="*50)
    print(f"{'STUDENT GRADE REPORT':^50}")
    print("="*50)
    
    for student, grades in students_grades.items():
        avg_grade = sum(grades) / len(grades)
        print(f"Student: {student:<20} Average: {avg_grade:>6.1f}%")
        
        # Show individual grades
        grade_str = ", ".join(f"{grade:.1f}" for grade in grades)
        print(f"  Grades: {grade_str}")
        print("-" * 30)

# Sample data
grade_data = {
    "Alice Johnson": [92.5, 87.0, 95.5, 89.0],
    "Bob Smith": [78.5, 82.0, 85.5, 80.0],
    "Carol Davis": [95.0, 98.5, 92.0, 96.5]
}

create_report(grade_data)