Package

A package is a folder containing one or more modules and a special file named __init__.py.
The __init__.py file can be empty or contain initialization code for the package.
Packages can also contain sub-packages (folders inside folders).

How to create a package:

Suppose you want a package named mytools with two modules, string_ops.py and number_ops.py.

Folder structure:

mytools/
    __init__.py
    string_ops.py
    number_ops.py

Example content:

# string_ops.py
def to_upper(text):
    return text.upper()

# number_ops.py
def multiply(a, b):
    return a * b

from mytools import string_ops, number_ops

print(string_ops.to_upper("hello"))  # Output: HELLO
print(number_ops.multiply(4, 5))     # Output: 20

Or import individual functions:

from mytools.string_ops import to_upper

print(to_upper("world"))  # Output: WORLD

It tells Python that the directory is a package.
It can be empty.
It can also be used to specify what is available when you import the package, by defining the __all__list or importing submodules inside it.

Example:

# __init__.py
from .string_ops import to_upper
from .number_ops import multiply

Now, you can directly import functions from the package:

from mytools import to_upper, multiply

print(to_upper("hey"))
print(multiply(3, 7))