Variables and Data Types

x = 10          # Integer
y = 3.14        # Float
name = "Alice"  # String
is_valid = True # Boolean

# Basic Arithmetic
a = 5 + 3
b = 7 - 2
c = 4 * 6
d = 8 / 2
e = 10 % 3  # Modulus (remainder)

# Strings
string1 = "Hello"
string2 = "World"
concatenated_string = string1 + " " + string2
string_length = len(concatenated_string)

# Lists (Ordered, Mutable)
my_list = [1, 2, 3, 4, 5]
list_length = len(my_list)
first_element = my_list[0]
my_list.append(6)
my_list.remove(3)

# Tuples (Ordered, Immutable)
my_tuple = (1, 2, 3)
element_2 = my_tuple[1]

# Dictionaries (Key-Value Pairs)
my_dict = {"name": "Alice", "age": 30}
name_value = my_dict["name"]
my_dict["city"] = "New York"
del my_dict["age"]

Conditional Statements

if x > y:
    print("x is greater than y")
elif x < y:
    print("x is less than y")
else:
    print("x is equal to y")

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

while condition:
    # code

# List Comprehensions
squares = [x**2 for x in range(5)]

Functions

def greet(name):
    return "Hello, " + name

result = greet("Bob")

# Lambda Functions
add = lambda x, y: x + y
result = add(3, 4)

# Importing Modules
import math
sqrt = math.sqrt(16)

File I/O

with open("file.txt", "r") as file:
    data = file.read()

# Exception Handling
try:
    result = 10 / 0
except ZeroDivisionError:
    print("Division by zero is not allowed.")

Classes and Objects

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def say_hello(self):
        return f"My name is {self.name} and I am {self.age} years old."

alice = Person("Alice", 30)
greeting = alice.say_hello()

Argparse Tutorial

https://docs.python.org/3/howto/argparse.html

This tutorial provides an introduction to argparse, the command-line parsing module in Python. Here are the key points covered:

  • argparse is used to handle command-line arguments and options, similar to the ls command in Unix.

  • Basic usage of argparse involves creating an ArgumentParser object and using the parse_args() method.

  • Positional arguments are required and their position matters, while optional arguments are not required and are usually preceded by - or --.

  • The --help or -h option is built-in and provides a help message.

  • Adding arguments is done with the add_argument() method, where you can specify the argument name, help text, and data type.

  • Optional arguments can be made to act as flags using action="store_true", which doesn’t require a value and defaults to False if not provided.

  • Short options can be specified alongside long options by passing them as additional arguments to add_argument().

  • Arguments can be combined, with optional arguments modifying the behavior or output format of the program.

  • Mutual exclusivity can be enforced using add_mutually_exclusive_group(), which ensures that conflicting options are not used together.

  • Verbosity levels can be handled by counting occurrences of an option using the action="count" argument.

  • The default keyword ensures a default value is set for optional arguments that are not provided.

  • More advanced use cases allow for the calculation of powers, not just squares, and adjusting program verbosity.

  • Ambiguities can be resolved with --, indicating that everything following is a positional argument.

  • Help messages and error texts from argparse are translatable using the gettext module for internationalization.

  • The tutorial concludes by emphasizing that there is much more to argparse than covered, and the official documentation contains detailed explanations and examples.