import os

print(os.path.exists("data.txt"))      # True or False
print(os.path.isfile("data.txt"))     # Checks file
print(os.path.isdir("new_folder"))    # Checks directory

False
False
True

import sys

print(sys.getrecursionlimit())  # Default ~1000

3000

class Student:
    school = "Global Academy"  # Class variable

    def __init__(self, name):
        self.name = name        # Instance variable

s1 = Student("Alice")
s2 = Student("Bob")

print(s1.school)
print(s2.school)

Global Academy
Global Academy

class ComplexNumber:
    def __init__(self, real):
        self.real = real

    def __add__(self, other):
        return ComplexNumber(self.real + other.real)

    def __sub__(self, other):
        return ComplexNumber(self.real - other.real)

    def __str__(self):
        return str(self.real)

c1 = ComplexNumber(10)
c2 = ComplexNumber(3)

print(c1 + c2)  # 13
print(c1 - c2)  # 7 …

even_numbers = [x for x in range(10) if x % 2 == 0]

class Parent:
    def __init__(self, name):
        self.name = name

class Child(Parent):
    def __init__(self, name, age):
        super().__init__(name)
        self.age = age

c = Child("Alice", 25)
print(c.name, c.age)

Alice 25

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

p = Person("Bob", 30)
print(p.name, p.age)

Bob 30

import csv

with open("data.csv", "r") as file:
    reader = csv.DictReader(file)
    for row in reader:
        age = int(row["age"])
        salary = float(row["salary"])
        print(age, salary)

---------------------------------------------------------------------------

KeyError                                  Traceback (most recent call last)

Cell In[1], line 7
      5 for row in reader:
      6     age = int(row["age"])
----> 7 …

class A:
    def __init__(self):
        print("A init")
        super().__init__()

class B:
    def __init__(self):
        print("B init")
        super().__init__()

class C(A, B):
    def __init__(self):
        print("C init")
        super().__init__()

c = C()

C init
A init
B init

import shutil

shutil.copy("source.txt", "backup.txt")
shutil.move("backup.txt", "archive/backup.txt")