Unit V: Python Packages & GUI Programming

# Install packages using pip (Python Package Installer)

# Basic installation
# pip install numpy
# pip install pandas
# pip install matplotlib

# Install specific version
# pip install numpy==1.21.0

# Install multiple packages
# pip install numpy pandas matplotlib

# Upgrade package
# pip install --upgrade numpy

# List installed packages
# pip list

# Uninstall package
# pip uninstall numpy

# Different ways to import

# Import entire module
import numpy
arr = numpy.array([1, 2, 3])

# Import with alias (common practice)
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt

arr = np.array([1, 2, 3])

# Import specific functions
from numpy import array, zeros, ones
arr = array([1, 2, 3])

# Import everything (not recommended)
from numpy import *
arr = array([1, 2, 3])

import numpy as np

# Creating arrays from lists
arr1 = np.array([1, 2, 3, 4, 5])
print("1D Array:", arr1)

# 2D Array (matrix)
arr2 = np.array([[1, 2, 3], [4, 5, 6]])
print("2D Array:\n", arr2)

# Special arrays
zeros = np.zeros((3, 4))      # 3x4 array of zeros
print("Zeros:\n", zeros)

ones = np.ones((2, 3))        # 2x3 array of ones
print("Ones:\n", ones)

identity = np.eye(3)          # 3x3 identity matrix
print("Identity:\n", identity)

# Range arrays
range_arr = np.arange(0, 10, 2)  # Start, stop, step
print("Range:", range_arr)  # [0 2 4 6 8]

# Evenly spaced values
linspace = np.linspace(0, 1, 5)  # 5 values from 0 to 1
print("Linspace:", linspace)  # [0.   0.25 0.5  0.75 1.  ]

# Random arrays
random_arr = np.random.rand(3, 3)  # 3x3 random values (0-1)
print("Random:\n", random_arr)

random_int = np.random.randint(1, 100, size=(3, 3))  # Random integers
print("Random Integers:\n", random_int)

import numpy as np

arr = np.array([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]])

# Array attributes
print("Shape:", arr.shape)      # (3, 4) - 3 rows, 4 columns
print("Dimensions:", arr.ndim)  # 2
print("Size:", arr.size)        # 12 (total elements)
print("Data type:", arr.dtype)  # int64

# Indexing
print("\nIndexing:")
print("Element [0,0]:", arr[0, 0])  # 1
print("Element [1,2]:", arr[1, 2])  # 7
print("Last element:", arr[-1, -1]) # 12

# Slicing
print("\nSlicing:")
print("First row:", arr[0])          # [1 2 3 4]
print("First column:", arr[:, 0])    # [1 5 9]
print("Subarray:", arr[0:2, 1:3])    # [[2 3] [6 7]]

# Boolean indexing
print("\nBoolean indexing:")
print("Elements > 5:", arr[arr > 5])  # [6 7 8 9 10 11 12]

# Reshape
reshaped = arr.reshape(4, 3)
print("\nReshaped (4x3):\n", reshaped)

# Flatten
flat = arr.flatten()
print("Flattened:", flat)  # [1 2 3 4 5 6 7 8 9 10 11 12]

import numpy as np

# Arithmetic operations (element-wise)
a = np.array([1, 2, 3, 4])
b = np.array([5, 6, 7, 8])

print("Addition:", a + b)        # [6 8 10 12]
print("Subtraction:", a - b)     # [-4 -4 -4 -4]
print("Multiplication:", a * b)  # [5 12 21 32]
print("Division:", b / a)        # [5. 3. 2.33... 2.]
print("Power:", a ** 2)          # [1 4 9 16]

# Scalar operations
print("\nScalar operations:")
print("a + 10:", a + 10)     # [11 12 13 14]
print("a * 2:", a * 2)       # [2 4 6 8]

# Mathematical functions
print("\nMath functions:")
print("Square root:", np.sqrt(a))     # [1. 1.41... 1.73... 2.]
print("Exponential:", np.exp(a))      # [2.72 7.39 20.09 54.60]
print("Logarithm:", np.log(a))        # [0. 0.69 1.10 1.39]
print("Sin:", np.sin(a))

# Aggregate functions
arr = np.array([[1, 2, 3], [4, 5, 6]])
print("\nAggregate functions:")
print("Sum:", np.sum(arr))        # 21
print("Mean:", np.mean(arr))      # 3.5
print("Max:", np.max(arr))        # 6
print("Min:", np.min(arr))        # 1
print("Std Dev:", np.std(arr))    # 1.707...

# Axis-wise operations
print("\nAxis operations:")
print("Sum (rows):", np.sum(arr, axis=1))    # [6 15]
print("Sum (columns):", np.sum(arr, axis=0)) # [5 7 9]
print("Mean (rows):", np.mean(arr, axis=1))  # [2. 5.]

# Matrix operations
A = np.array([[1, 2], [3, 4]])
B = np.array([[5, 6], [7, 8]])

print("\nMatrix operations:")
print("Matrix multiply:\n", np.dot(A, B))  # or A @ B
print("Transpose:\n", A.T)
print("Determinant:", np.linalg.det(A))

import pandas as pd
import numpy as np

# Series - 1D labeled array
s = pd.Series([10, 20, 30, 40, 50])
print("Series:")
print(s)

# Series with custom index
s = pd.Series([10, 20, 30], index=['a', 'b', 'c'])
print("\nSeries with index:")
print(s)
print("Access 'b':", s['b'])  # 20

# DataFrame - 2D labeled data structure
data = {
    'Name': ['Alice', 'Bob', 'Charlie', 'David'],
    'Age': [25, 30, 35, 28],
    'City': ['New York', 'Boston', 'Chicago', 'Seattle'],
    'Salary': [50000, 60000, 75000, 55000]
}

df = pd.DataFrame(data)
print("\nDataFrame:")
print(df)

# DataFrame from list of lists
data = [
    ['Alice', 25, 'New York'],
    ['Bob', 30, 'Boston'],
    ['Charlie', 35, 'Chicago']
]
df = pd.DataFrame(data, columns=['Name', 'Age', 'City'])
print("\nFrom list:")
print(df)

import pandas as pd

# Create sample DataFrame
df = pd.DataFrame({
    'Name': ['Alice', 'Bob', 'Charlie'],
    'Age': [25, 30, 35],
    'Score': [85, 92, 78]
})

# Save to CSV
df.to_csv('students.csv', index=False)
print("Saved to CSV")

# Read from CSV
df_read = pd.read_csv('students.csv')
print("\nRead from CSV:")
print(df_read)

# Save to Excel (requires openpyxl)
# df.to_excel('students.xlsx', index=False)

# Read from Excel
# df_excel = pd.read_excel('students.xlsx')

# Read from JSON
# df_json = pd.read_json('data.json')

# Display first/last rows
print("\nFirst 2 rows:")
print(df.head(2))

print("\nLast 2 rows:")
print(df.tail(2))

# DataFrame info
print("\nInfo:")
print(df.info())

print("\nStatistics:")
print(df.describe())

import pandas as pd

df = pd.DataFrame({
    'Name': ['Alice', 'Bob', 'Charlie', 'David', 'Eve'],
    'Age': [25, 30, 35, 28, 32],
    'City': ['NYC', 'Boston', 'NYC', 'Seattle', 'Boston'],
    'Salary': [50000, 60000, 75000, 55000, 65000]
})

# Column selection
print("Names:", df['Name'].tolist())
print("\nMultiple columns:")
print(df[['Name', 'Age']])

# Row selection with iloc (index-based)
print("\nFirst row:")
print(df.iloc[0])

print("\nRows 1-3:")
print(df.iloc[1:4])

# Row selection with loc (label-based)
df.index = ['a', 'b', 'c', 'd', 'e']
print("\nRow 'b':")
print(df.loc['b'])

# Conditional filtering
print("\nAge > 28:")
print(df[df['Age'] > 28])

print("\nNYC residents:")
print(df[df['City'] == 'NYC'])

# Multiple conditions
print("\nAge > 25 AND Salary > 55000:")
print(df[(df['Age'] > 25) & (df['Salary'] > 55000)])

# Query method (alternative)
print("\nUsing query:")
print(df.query('Age > 30'))

import pandas as pd
import numpy as np

df = pd.DataFrame({
    'Name': ['Alice', 'Bob', 'Charlie', 'David'],
    'Age': [25, 30, None, 28],
    'Salary': [50000, 60000, 75000, 55000],
    'Department': ['IT', 'HR', 'IT', 'Finance']
})

# Adding new column
df['Bonus'] = df['Salary'] * 0.1
print("With Bonus column:")
print(df)

# Modifying column
df['Age'] = df['Age'].fillna(df['Age'].mean())
print("\nFilled missing age:")
print(df)

# Dropping columns
df_dropped = df.drop('Bonus', axis=1)
print("\nDropped Bonus:")
print(df_dropped)

# Sorting
print("\nSorted by Age:")
print(df.sort_values('Age'))

print("\nSorted by multiple columns:")
print(df.sort_values(['Department', 'Salary'], ascending=[True, False]))

# Grouping
print("\nGrouped by Department:")
print(df.groupby('Department')['Salary'].mean())

# Aggregation
print("\nMultiple aggregations:")
print(df.groupby('Department').agg({
    'Salary': ['mean', 'sum'],
    'Age': 'mean'
}))

# Apply function
df['Salary_Category'] = df['Salary'].apply(
    lambda x: 'High' if x > 55000 else 'Low'
)
print("\nWith category:")
print(df)

import matplotlib.pyplot as plt
import numpy as np

# Simple line plot
x = [1, 2, 3, 4, 5]
y = [2, 4, 6, 8, 10]

plt.plot(x, y)
plt.title('Simple Line Plot')
plt.xlabel('X-axis')
plt.ylabel('Y-axis')
plt.show()

# Line plot with styling
x = np.linspace(0, 10, 100)
y1 = np.sin(x)
y2 = np.cos(x)

plt.figure(figsize=(10, 6))
plt.plot(x, y1, 'b-', label='sin(x)', linewidth=2)
plt.plot(x, y2, 'r--', label='cos(x)', linewidth=2)
plt.title('Trigonometric Functions')
plt.xlabel('x')
plt.ylabel('y')
plt.legend()
plt.grid(True)
plt.show()

import matplotlib.pyplot as plt
import numpy as np

# Bar Chart
categories = ['A', 'B', 'C', 'D', 'E']
values = [23, 45, 56, 78, 32]

plt.figure(figsize=(8, 5))
plt.bar(categories, values, color='steelblue')
plt.title('Bar Chart')
plt.xlabel('Categories')
plt.ylabel('Values')
plt.show()

# Pie Chart
sizes = [30, 25, 20, 15, 10]
labels = ['Python', 'JavaScript', 'Java', 'C++', 'Other']
explode = (0.1, 0, 0, 0, 0)  # Explode first slice

plt.figure(figsize=(8, 8))
plt.pie(sizes, labels=labels, explode=explode, autopct='%1.1f%%',
        shadow=True, startangle=90)
plt.title('Programming Language Usage')
plt.show()

# Scatter Plot
np.random.seed(42)
x = np.random.randn(100)
y = 2*x + np.random.randn(100)

plt.figure(figsize=(8, 6))
plt.scatter(x, y, c='blue', alpha=0.6)
plt.title('Scatter Plot')
plt.xlabel('X')
plt.ylabel('Y')
plt.show()

# Histogram
data = np.random.randn(1000)

plt.figure(figsize=(8, 6))
plt.hist(data, bins=30, color='green', alpha=0.7, edgecolor='black')
plt.title('Histogram')
plt.xlabel('Value')
plt.ylabel('Frequency')
plt.show()

import matplotlib.pyplot as plt
import numpy as np

# Multiple subplots
fig, axes = plt.subplots(2, 2, figsize=(12, 10))

# Subplot 1: Line plot
x = np.linspace(0, 10, 100)
axes[0, 0].plot(x, np.sin(x), 'b-')
axes[0, 0].set_title('Sine Wave')
axes[0, 0].set_xlabel('x')
axes[0, 0].set_ylabel('sin(x)')

# Subplot 2: Bar chart
categories = ['A', 'B', 'C', 'D']
values = [25, 40, 30, 55]
axes[0, 1].bar(categories, values, color='orange')
axes[0, 1].set_title('Bar Chart')

# Subplot 3: Scatter plot
x = np.random.randn(50)
y = x + np.random.randn(50)
axes[1, 0].scatter(x, y, c='green', alpha=0.6)
axes[1, 0].set_title('Scatter Plot')

# Subplot 4: Pie chart
sizes = [35, 30, 20, 15]
axes[1, 1].pie(sizes, labels=categories, autopct='%1.1f%%')
axes[1, 1].set_title('Pie Chart')

plt.tight_layout()
plt.savefig('subplots.png', dpi=300)  # Save figure
plt.show()

# Customizing plot appearance
plt.style.use('seaborn-v0_8-darkgrid')  # Use a style

x = np.linspace(0, 10, 100)
plt.figure(figsize=(10, 6))

plt.plot(x, np.sin(x), 'b-', label='sin', linewidth=2)
plt.plot(x, np.cos(x), 'r--', label='cos', linewidth=2)

plt.title('Customized Plot', fontsize=16, fontweight='bold')
plt.xlabel('X-axis', fontsize=12)
plt.ylabel('Y-axis', fontsize=12)
plt.legend(loc='upper right', fontsize=10)
plt.xlim(0, 10)
plt.ylim(-1.5, 1.5)
plt.grid(True, alpha=0.3)

plt.show()

import tkinter as tk

# Create main window
root = tk.Tk()

# Window properties
root.title("My First GUI App")
root.geometry("400x300")  # Width x Height
root.resizable(True, True)  # Allow resize

# Configure background color
root.configure(bg='lightblue')

# Add a label
label = tk.Label(root, text="Hello, Tkinter!", 
                 font=("Arial", 24), 
                 bg='lightblue')
label.pack(pady=50)

# Start the event loop
root.mainloop()

import tkinter as tk

root = tk.Tk()

# Window title
root.title("Configured Window")

# Window size and position
# Format: "widthxheight+x_position+y_position"
root.geometry("500x400+100+100")

# Minimum and maximum size
root.minsize(300, 200)
root.maxsize(800, 600)

# Icon (if available)
# root.iconbitmap('icon.ico')

# Full screen mode
# root.attributes('-fullscreen', True)

# Always on top
# root.attributes('-topmost', True)

# Transparency (0.0 = invisible, 1.0 = opaque)
root.attributes('-alpha', 0.95)

# Disable/enable window controls
# root.resizable(False, False)  # Disable resize

# Handle window close
def on_close():
    print("Window closing...")
    root.destroy()

root.protocol("WM_DELETE_WINDOW", on_close)

root.mainloop()

import tkinter as tk

root = tk.Tk()
root.title("Labels and Buttons")
root.geometry("400x300")

# Label widget
label = tk.Label(root, 
                 text="Welcome to Tkinter!", 
                 font=("Arial", 18, "bold"),
                 fg="blue",
                 bg="lightyellow",
                 padx=20, pady=10)
label.pack(pady=20)

# Variable to update label
click_count = tk.IntVar(value=0)

def button_click():
    count = click_count.get() + 1
    click_count.set(count)
    result_label.config(text=f"Button clicked {count} times!")

# Button widget
button = tk.Button(root, 
                   text="Click Me!", 
                   command=button_click,
                   font=("Arial", 14),
                   bg="green", fg="white",
                   padx=20, pady=10,
                   activebackground="darkgreen")
button.pack(pady=10)

# Result label
result_label = tk.Label(root, text="Button not clicked yet",
                        font=("Arial", 12))
result_label.pack(pady=10)

# Quit button
quit_button = tk.Button(root, text="Quit", 
                        command=root.destroy,
                        bg="red", fg="white")
quit_button.pack(pady=20)

root.mainloop()

import tkinter as tk

root = tk.Tk()
root.title("Input Widgets")
root.geometry("450x400")

# Single-line Entry
tk.Label(root, text="Name:", font=("Arial", 12)).pack(pady=(20, 5))
name_entry = tk.Entry(root, font=("Arial", 12), width=30)
name_entry.pack(pady=5)
name_entry.insert(0, "Enter your name")  # Default text

# Password Entry
tk.Label(root, text="Password:", font=("Arial", 12)).pack(pady=(10, 5))
password_entry = tk.Entry(root, font=("Arial", 12), width=30, show="*")
password_entry.pack(pady=5)

# Multi-line Text widget
tk.Label(root, text="Message:", font=("Arial", 12)).pack(pady=(10, 5))
text_widget = tk.Text(root, height=5, width=35, font=("Arial", 11))
text_widget.pack(pady=5)
text_widget.insert("1.0", "Enter your message here...")

def submit():
    name = name_entry.get()
    password = password_entry.get()
    message = text_widget.get("1.0", tk.END).strip()
    
    result = f"Name: {name}\nMessage: {message}"
    output_label.config(text=result)

def clear():
    name_entry.delete(0, tk.END)
    password_entry.delete(0, tk.END)
    text_widget.delete("1.0", tk.END)

# Buttons
button_frame = tk.Frame(root)
button_frame.pack(pady=10)

submit_btn = tk.Button(button_frame, text="Submit", command=submit,
                       bg="blue", fg="white", padx=20)
submit_btn.pack(side=tk.LEFT, padx=10)

clear_btn = tk.Button(button_frame, text="Clear", command=clear,
                      bg="gray", fg="white", padx=20)
clear_btn.pack(side=tk.LEFT, padx=10)

# Output label
output_label = tk.Label(root, text="", font=("Arial", 10), 
                        justify=tk.LEFT)
output_label.pack(pady=10)

root.mainloop()

import tkinter as tk

# pack() - Simple layout
def pack_demo():
    win = tk.Toplevel()
    win.title("Pack Demo")
    win.geometry("300x200")
    
    tk.Label(win, text="Top", bg="red", fg="white").pack(fill=tk.X)
    tk.Label(win, text="Bottom", bg="blue", fg="white").pack(side=tk.BOTTOM, fill=tk.X)
    tk.Label(win, text="Left", bg="green", fg="white").pack(side=tk.LEFT, fill=tk.Y)
    tk.Label(win, text="Right", bg="yellow").pack(side=tk.RIGHT, fill=tk.Y)
    tk.Label(win, text="Center", bg="purple", fg="white").pack(expand=True, fill=tk.BOTH)

# grid() - Table-like layout
def grid_demo():
    win = tk.Toplevel()
    win.title("Grid Demo")
    
    tk.Label(win, text="Username:").grid(row=0, column=0, padx=10, pady=10, sticky="e")
    tk.Entry(win).grid(row=0, column=1, padx=10, pady=10)
    
    tk.Label(win, text="Password:").grid(row=1, column=0, padx=10, pady=10, sticky="e")
    tk.Entry(win, show="*").grid(row=1, column=1, padx=10, pady=10)
    
    tk.Button(win, text="Login").grid(row=2, column=0, columnspan=2, pady=20)

# place() - Absolute positioning
def place_demo():
    win = tk.Toplevel()
    win.title("Place Demo")
    win.geometry("300x200")
    
    tk.Button(win, text="Button 1").place(x=50, y=50)
    tk.Button(win, text="Button 2").place(x=150, y=100)
    tk.Button(win, text="Centered", width=10).place(relx=0.5, rely=0.5, anchor=tk.CENTER)

# Main window
root = tk.Tk()
root.title("Layout Managers")
root.geometry("300x200")

tk.Button(root, text="Pack Demo", command=pack_demo, width=20).pack(pady=20)
tk.Button(root, text="Grid Demo", command=grid_demo, width=20).pack(pady=10)
tk.Button(root, text="Place Demo", command=place_demo, width=20).pack(pady=10)

root.mainloop()

import tkinter as tk

root = tk.Tk()
root.title("Selection Widgets")
root.geometry("400x350")

# Checkbuttons
tk.Label(root, text="Select your hobbies:", font=("Arial", 12, "bold")).pack(pady=10)

hobby1 = tk.BooleanVar()
hobby2 = tk.BooleanVar()
hobby3 = tk.BooleanVar()

tk.Checkbutton(root, text="Reading", variable=hobby1, 
               font=("Arial", 11)).pack(anchor="w", padx=50)
tk.Checkbutton(root, text="Gaming", variable=hobby2,
               font=("Arial", 11)).pack(anchor="w", padx=50)
tk.Checkbutton(root, text="Sports", variable=hobby3,
               font=("Arial", 11)).pack(anchor="w", padx=50)

# Separator
tk.Frame(root, height=2, bg="gray").pack(fill="x", pady=20)

# Radio buttons
tk.Label(root, text="Select your gender:", font=("Arial", 12, "bold")).pack(pady=10)

gender = tk.StringVar(value="")

tk.Radiobutton(root, text="Male", variable=gender, value="Male",
               font=("Arial", 11)).pack(anchor="w", padx=50)
tk.Radiobutton(root, text="Female", variable=gender, value="Female",
               font=("Arial", 11)).pack(anchor="w", padx=50)
tk.Radiobutton(root, text="Other", variable=gender, value="Other",
               font=("Arial", 11)).pack(anchor="w", padx=50)

def show_selection():
    hobbies = []
    if hobby1.get(): hobbies.append("Reading")
    if hobby2.get(): hobbies.append("Gaming")
    if hobby3.get(): hobbies.append("Sports")
    
    result = f"Hobbies: {', '.join(hobbies) or 'None'}\nGender: {gender.get() or 'Not selected'}"
    result_label.config(text=result)

tk.Button(root, text="Show Selection", command=show_selection,
          bg="blue", fg="white", padx=20).pack(pady=20)

result_label = tk.Label(root, text="", font=("Arial", 10))
result_label.pack()

root.mainloop()

import tkinter as tk

class Calculator:
    def __init__(self, root):
        self.root = root
        self.root.title("Calculator")
        self.root.geometry("300x400")
        self.root.resizable(False, False)
        
        self.expression = ""
        
        # Display
        self.display = tk.Entry(root, font=("Arial", 24), 
                                justify="right", bd=10)
        self.display.grid(row=0, column=0, columnspan=4, 
                         sticky="nsew", padx=5, pady=5)
        
        # Button layout
        buttons = [
            ('C', 1, 0), ('±', 1, 1), ('%', 1, 2), ('/', 1, 3),
            ('7', 2, 0), ('8', 2, 1), ('9', 2, 2), ('*', 2, 3),
            ('4', 3, 0), ('5', 3, 1), ('6', 3, 2), ('-', 3, 3),
            ('1', 4, 0), ('2', 4, 1), ('3', 4, 2), ('+', 4, 3),
            ('0', 5, 0, 2), ('.', 5, 2), ('=', 5, 3)
        ]
        
        for btn in buttons:
            text = btn[0]
            row = btn[1]
            col = btn[2]
            colspan = btn[3] if len(btn) > 3 else 1
            
            button = tk.Button(root, text=text, font=("Arial", 18),
                              command=lambda t=text: self.click(t))
            button.grid(row=row, column=col, columnspan=colspan,
                       sticky="nsew", padx=2, pady=2)
        
        # Configure grid weights
        for i in range(6):
            root.grid_rowconfigure(i, weight=1)
        for i in range(4):
            root.grid_columnconfigure(i, weight=1)
    
    def click(self, char):
        if char == 'C':
            self.expression = ""
        elif char == '=':
            try:
                self.expression = str(eval(self.expression))
            except:
                self.expression = "Error"
        elif char == '±':
            try:
                self.expression = str(-float(self.expression))
            except:
                pass
        elif char == '%':
            try:
                self.expression = str(float(self.expression) / 100)
            except:
                pass
        else:
            self.expression += char
        
        self.display.delete(0, tk.END)
        self.display.insert(0, self.expression)

root = tk.Tk()
app = Calculator(root)
root.mainloop()

import tkinter as tk
from tkinter import messagebox

class TodoApp:
    def __init__(self, root):
        self.root = root
        self.root.title("To-Do List")
        self.root.geometry("400x500")
        
        # Title
        title = tk.Label(root, text="My To-Do List", 
                        font=("Arial", 20, "bold"))
        title.pack(pady=20)
        
        # Input frame
        input_frame = tk.Frame(root)
        input_frame.pack(pady=10)
        
        self.task_entry = tk.Entry(input_frame, font=("Arial", 14), 
                                   width=25)
        self.task_entry.pack(side=tk.LEFT, padx=5)
        
        add_btn = tk.Button(input_frame, text="Add", 
                           command=self.add_task,
                           bg="green", fg="white",
                           font=("Arial", 12))
        add_btn.pack(side=tk.LEFT)
        
        # Listbox with scrollbar
        list_frame = tk.Frame(root)
        list_frame.pack(pady=20, fill=tk.BOTH, expand=True, padx=20)
        
        scrollbar = tk.Scrollbar(list_frame)
        scrollbar.pack(side=tk.RIGHT, fill=tk.Y)
        
        self.task_list = tk.Listbox(list_frame, font=("Arial", 14),
                                    height=10, selectmode=tk.SINGLE,
                                    yscrollcommand=scrollbar.set)
        self.task_list.pack(fill=tk.BOTH, expand=True)
        scrollbar.config(command=self.task_list.yview)
        
        # Buttons frame
        btn_frame = tk.Frame(root)
        btn_frame.pack(pady=10)
        
        complete_btn = tk.Button(btn_frame, text="Mark Complete",
                                command=self.mark_complete,
                                bg="blue", fg="white",
                                font=("Arial", 11))
        complete_btn.pack(side=tk.LEFT, padx=5)
        
        delete_btn = tk.Button(btn_frame, text="Delete",
                              command=self.delete_task,
                              bg="red", fg="white",
                              font=("Arial", 11))
        delete_btn.pack(side=tk.LEFT, padx=5)
        
        clear_btn = tk.Button(btn_frame, text="Clear All",
                             command=self.clear_all,
                             bg="gray", fg="white",
                             font=("Arial", 11))
        clear_btn.pack(side=tk.LEFT, padx=5)
        
        # Status bar
        self.status = tk.Label(root, text="Tasks: 0", 
                              font=("Arial", 10))
        self.status.pack(pady=10)
    
    def add_task(self):
        task = self.task_entry.get().strip()
        if task:
            self.task_list.insert(tk.END, f"☐ {task}")
            self.task_entry.delete(0, tk.END)
            self.update_status()
        else:
            messagebox.showwarning("Warning", "Please enter a task!")
    
    def mark_complete(self):
        try:
            index = self.task_list.curselection()[0]
            task = self.task_list.get(index)
            if task.startswith("☐"):
                self.task_list.delete(index)
                self.task_list.insert(index, task.replace("☐", "✓"))
                self.task_list.itemconfig(index, fg="green")
        except IndexError:
            messagebox.showinfo("Info", "Please select a task!")
    
    def delete_task(self):
        try:
            index = self.task_list.curselection()[0]
            self.task_list.delete(index)
            self.update_status()
        except IndexError:
            messagebox.showinfo("Info", "Please select a task!")
    
    def clear_all(self):
        if messagebox.askyesno("Confirm", "Delete all tasks?"):
            self.task_list.delete(0, tk.END)
            self.update_status()
    
    def update_status(self):
        count = self.task_list.size()
        self.status.config(text=f"Tasks: {count}")

root = tk.Tk()
app = TodoApp(root)
root.mainloop()

import tkinter as tk
from tkinter import ttk

class TemperatureConverter:
    def __init__(self, root):
        self.root = root
        self.root.title("Temperature Converter")
        self.root.geometry("350x250")
        
        # Title
        tk.Label(root, text="Temperature Converter",
                font=("Arial", 16, "bold")).pack(pady=20)
        
        # Input frame
        input_frame = tk.Frame(root)
        input_frame.pack(pady=10)
        
        self.temp_var = tk.StringVar()
        temp_entry = tk.Entry(input_frame, textvariable=self.temp_var,
                             font=("Arial", 14), width=15)
        temp_entry.pack(side=tk.LEFT, padx=5)
        
        self.unit_var = tk.StringVar(value="Celsius")
        unit_combo = ttk.Combobox(input_frame, textvariable=self.unit_var,
                                  values=["Celsius", "Fahrenheit", "Kelvin"],
                                  state="readonly", width=12)
        unit_combo.pack(side=tk.LEFT)
        
        # Convert button
        tk.Button(root, text="Convert", command=self.convert,
                 bg="blue", fg="white", font=("Arial", 12),
                 padx=30).pack(pady=20)
        
        # Results
        self.result_label = tk.Label(root, text="", font=("Arial", 12))
        self.result_label.pack(pady=10)
    
    def convert(self):
        try:
            temp = float(self.temp_var.get())
            unit = self.unit_var.get()
            
            # Convert to Celsius first
            if unit == "Celsius":
                celsius = temp
            elif unit == "Fahrenheit":
                celsius = (temp - 32) * 5/9
            else:  # Kelvin
                celsius = temp - 273.15
            
            # Convert from Celsius to all units
            fahrenheit = (celsius * 9/5) + 32
            kelvin = celsius + 273.15
            
            result = f"Celsius: {celsius:.2f}°C\n"
            result += f"Fahrenheit: {fahrenheit:.2f}°F\n"
            result += f"Kelvin: {kelvin:.2f}K"
            
            self.result_label.config(text=result)
            
        except ValueError:
            self.result_label.config(text="Please enter a valid number!")

root = tk.Tk()
app = TemperatureConverter(root)
root.mainloop()

# 1. Install VS Code from https://code.visualstudio.com

# 2. Install Python extension
#    - Open Extensions (Ctrl+Shift+X)
#    - Search "Python"
#    - Install Microsoft's Python extension

# 3. Select Python interpreter
#    - Ctrl+Shift+P → "Python: Select Interpreter"
#    - Choose your Python installation

# 4. Create a Python file
#    - Create new file with .py extension
#    - Write your code

# 5. Run Python code
#    - Right-click → Run Python File in Terminal
#    - Or press F5 to debug

# 6. Useful extensions:
#    - Pylint (linting)
#    - Python Docstring Generator
#    - Jupyter (for notebooks)
#    - Code Runner

# 7. settings.json (optional)
{
    "python.linting.enabled": true,
    "python.linting.pylintEnabled": true,
    "python.formatting.provider": "black",
    "editor.formatOnSave": true
}

# Method 1: Command Line
# Open terminal/command prompt
# python filename.py

# Method 2: IDE Run Button
# Click the "Run" button or press F5

# Method 3: Interactive Mode
# Type 'python' in terminal to open interpreter
# >>> print("Hello")
# Hello
# >>> exit()

# Method 4: Python IDLE
# Open IDLE → File → New File → Write code → Run

# Method 5: Jupyter Notebook
# jupyter notebook
# Create new notebook → Write code in cells → Run cells