npc

1. String Functions
def my_concatenation(str1, str2):
    result = ""
    for char in str1:
        result += char
    for char in str2:
        result += char
    return result

def my_reverse(string):
    result = ""
    for i in range(len(string) - 1, -1, -1):
        result += string[i]
    return result

def my_replication(string, n):
    result = ""
    for _ in range(n):
        result = my_concatenation(result, string)
    return result

def my_slicing(string, start, end):
    result = ""
    for i in range(start, end):
        result += string[i]
    return result

def my_equals(str1, str2):
    if len(str1) != len(str2):
        return False
    for i in range(len(str1)):
        if str1[i] != str2[i]:
            return False
    return True

def my_iterate_string(string):
    for char in string:
        print(char, end=" ")

def my_substring(string, start, length):
    result = ""
    for i in range(start, start + length):
        result += string[i]
    return result

# Example usage
string1 = "Hello"
string2 = "World"
concatenated_str = my_concatenation(string1, string2)
reversed_str = my_reverse(string1)
replicated_str = my_replication(string1, 3)
sliced_str = my_slicing(string1, 1, 4)
equal_check = my_equals(string1, string2)
print("Concatenated String:", concatenated_str)
print("Reversed String:", reversed_str)
print("Replicated String:", replicated_str)
print("Sliced String:", sliced_str)
print("Equals Check:", equal_check)

print("\nIterating over the string:")
my_iterate_string(string1)

substring_str = my_substring(string1, 1, 3)
print("\nSubstring:", substring_str)

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2. Basic Regular Expression
import re

print("Matching a pattern")
pattern = r"apple"
text = "I like apples and oranges."

print("Using re.search() to find the first occurrence of the pattern")
match = re.search(pattern, text)
if match:
    print(f"Pattern '{pattern}' found at index {match.start()} in the text.")
else:
    print(f"Pattern '{pattern}' not found in the text.")

print("\nExtracting matches using groups")
pattern_with_groups = r"(\w+) (\w+)"
name_text = "John Doe, Jane Smith"

print("Using re.findall() to find all occurrences of the pattern with groups")
matches = re.findall(pattern_with_groups, name_text)
for match in matches:
    first_name, last_name = match
    print(f"First Name: {first_name}, Last Name: {last_name}")

print("\nReplacing matches")
pattern_to_replace = r"apple|orange"
replacement_text = "fruit"

print("Using re.sub() to replace all occurrences of the pattern")
updated_text = re.sub(pattern_to_replace, replacement_text, text)
print(f"Original Text: {text}")
print(f"Updated Text: {updated_text}")

-----
import re

# Function to demonstrate basic regular expressions
def demonstrate_regex(text):
    # 1. Matching a specific pattern
    pattern1 = re.compile(r'apple')
    match1 = pattern1.search(text)
    print("1. Matching 'apple':", match1.group() if match1 else "Not Found")

    # 2. Matching any digit
    pattern2 = re.compile(r'\d')
    match2 = pattern2.search(text)
    print("2. Matching any digit:", match2.group() if match2 else "Not Found")

    # 3. Matching any word character
    pattern3 = re.compile(r'\w+')
    match3 = pattern3.findall(text)
    print("3. Matching any word character:", match3)

    # 4. Matching any non-word character
    pattern4 = re.compile(r'\W+')
    match4 = pattern4.findall(text)
    print("4. Matching any non-word character:", match4)

    # 5. Matching a specific number of occurrences
    pattern5 = re.compile(r'o{2}')
    match5 = pattern5.search(text)
    print("5. Matching 'oo':", match5.group() if match5 else "Not Found")

    # 6. Matching the start of a string
    pattern6 = re.compile(r'^Hello')
    match6 = pattern6.search(text)
    print("6. Matching 'Hello' at the start:", match6.group() if match6 else "Not Found")

    # 7. Matching the end of a string
    pattern7 = re.compile(r'World$')
    match7 = pattern7.search(text)
    print("7. Matching 'World' at the end:", match7.group() if match7 else "Not Found")

    # 8. Matching any character (except for a newline)
    pattern8 = re.compile(r'.')
    match8 = pattern8.findall(text)
    print("8. Matching any character:", match8)

# Example usage
sample_text = "Hello apple! 123 World."
demonstrate_regex(sample_text)

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doubtful

3. Advanced Regular Expressions using Tkinter
import re
import tkinter as tk
from tkinter import ttk

def validate_input():
    name = name_entry.get()
    email = email_entry.get()
    phone = phone_entry.get()

    # Regular expressions for validation
    name_pattern = re.compile(r'^[A-Za-z\s]+$')
    email_pattern = re.compile(r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$')
    phone_pattern = re.compile(r'^\d{10}$')

    # Validate name
    if not name_pattern.match(name):
        result_label.config(text="Invalid name format", fg="red")
        return

    # Validate email
    if not email_pattern.match(email):
        result_label.config(text="Invalid email format", fg="red")
        return

    # Validate phone number
    if not phone_pattern.match(phone):
        result_label.config(text="Invalid phone number format", fg="red")
        return

    result_label.config(text="Input is valid", fg="green")

# Create the main application window
app = tk.Tk()
app.title("Data Validation")
app.geometry("300x200")

# Create and set up the form
frame = ttk.Frame(app, padding="10")
frame.grid(column=0, row=0, sticky=(tk.W, tk.E, tk.N, tk.S))

name_label = ttk.Label(frame, text="Name:")
name_label.grid(column=0, row=0, sticky=tk.W, pady=5)
name_entry = ttk.Entry(frame, width=30)
name_entry.grid(column=1, row=0, sticky=tk.W, pady=5)

email_label = ttk.Label(frame, text="Email:")
email_label.grid(column=0, row=1, sticky=tk.W, pady=5)
email_entry = ttk.Entry(frame, width=30)
email_entry.grid(column=1, row=1, sticky=tk.W, pady=5)

phone_label = ttk.Label(frame, text="Phone:")
phone_label.grid(column=0, row=2, sticky=tk.W, pady=5)
phone_entry = ttk.Entry(frame, width=15)
phone_entry.grid(column=1, row=2, sticky=tk.W, pady=5)

validate_button = ttk.Button(frame, text="Validate", command=validate_input)
validate_button.grid(column=0, row=3, columnspan=2, pady=10)

result_label = ttk.Label(frame, text="")
result_label.grid(column=0, row=4, columnspan=2)

# Run the Tkinter event loop
app.mainloop()

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4. Calculator using Tkinter
import tkinter as tk
from tkinter import ttk

def on_click(button_text):
    current_text = entry_var.get()

    if button_text == "C":
        entry_var.set("")
    elif button_text == "=":
        try:
            result = eval(current_text)
            entry_var.set(str(result))
        except Exception as e:
            entry_var.set("Error")
    else:
        entry_var.set(current_text + button_text)

# Create the main application window
calculator = tk.Tk()
calculator.title("Calculator")

# Entry widget for displaying the input and result
entry_var = tk.StringVar()
entry = ttk.Entry(calculator, textvariable=entry_var, font=('Arial', 14), justify="right")
entry.grid(row=0, column=0, columnspan=4, sticky="nsew", pady=10)
calculator.columnconfigure((0, 1, 2, 3), weight=1)

# Button layout
buttons = [
    '7', '8', '9', '/',
    '4', '5', '6', '*',
    '1', '2', '3', '-',
    '0', '.', 'C', '+',
    '='
]

# Add buttons to the grid
row_val = 1
col_val = 0

for button_text in buttons:
    ttk.Button(calculator, text=button_text, command=lambda text=button_text: on_click(text)).grid(row=row_val, column=col_val, sticky="nsew", padx=5, pady=5)
    col_val += 1
    if col_val > 3:
        col_val = 0
        row_val += 1

# Configure row and column weights
for i in range(1, 6):
    calculator.rowconfigure(i, weight=1)

# Run the Tkinter event loop
calculator.mainloop()