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python-barcode library.pip install python-barcode pillow
Pillow library is used to save in PNG format via ImageWriter.writer for working with images:import barcode
from barcode.writer import ImageWriter
EAN-13 barcode. Important: exactly 12 digits are passed, and the check digit is automatically calculated and added.ean = barcode.get(
"ean13",
"590123412345",
writer=ImageWriter()
)
filename = ean.save("product_barcode")
print(filename)product_barcode.png file will be created in the current directory.codes = [
"123456789012",
"987654321098",
"111222333444"
]
for value in codes:
code_obj = barcode.get(
"ean13",
value,
writer=ImageWriter()
)
code_obj.save(f"barcode_{value}")
EAN-13, otherwise the library will throw an exception.Code128:code128 = barcode.get(
"code128",
"ORDER-2025-001",
writer=ImageWriter()
)
code128.save("order_barcode")
APIs:def generate_barcode(value, filename):
code = barcode.get(
"code128",
value,
writer=ImageWriter()
)
return code.save(filename)
generate_barcode("INVOICE-4587", "invoice_4587")
__init__, __repr__ and __eq__ for each class? Dataclasses do it for you.class Point:
def __init__(self, x, y):
self.x = x
self.y = y
def __repr__(self):
return f"Point(x={self.x}, y={self.y})"
def __eq__(self, other):
return self.x == other.x and self.y == other.y
class User:
def __init__(self, name, age):
self.name = name
self.age = age
def __repr__(self):
return f"User(name={self.name}, age={self.age})"
def __eq__(self, other):
return self.name == other.name and self.age == other.age
from dataclasses import dataclass
@dataclass
class Point:
x: int
y: int
@dataclass
class User:
name: str
age: int
p1 = Point(10, 20)
p2 = Point(10, 20)
u = User("Ivan", 30)
print(p1) # Point(x=10, y=20)
print(p1 == p2) # True
print(u) # User(name='Ivan', age=30)
from dataclasses import dataclass, fieldinits generated by default?:
@dataclass(order=True, frozen=True)
class Product:
name: str
price: float = 0.0
tags: list[str] = field(default_factory=list, compare=False)
def expensive(self):
return self.price > 1000
p1 = Product("Laptop", 1500.0)
p2 = Product("Mouse", 50.0)
print(p1 > p2) # True (price comparison due to order=True)
p1.tags.append("tech")
# p1.name = "PC" # Error! frozen=True makes the object immutable
🔵 __initreprtializer with parametersare not a replacement for regular classes. Use them for data structures where standard methods are needed.
🔵 __repr_eqetty string representation
🔵 __eq__ - comparison acltllles
gth geTrue: __lt__, __le__, __gt__, __ge__
Important:
Dataclasses
Forwarded from Machine Learning with Python
Forwarded from Remote Jobs — Daily LinkedIn Picks 💼
.format() in everyday code, but their capabilities are not always fully utilized. They support formatting, function calls, working with data structures, and convenient debugging (from 3.8+).rows = [
("id", "name", "role"),
(1, "Ivan", "admin"),
(2, "Olga", "editor"),
]
for r in rows:
print(f"{r[0]:<5} {r[1]:<10} {r[2]:<10}")
{x=> displays the name and value of the variable, which speeds up debugging. Supports formatting of calculations:x = 12
y = 7
print(f"{x=} {y=} {x*y=} x/y={x/y:.3f}")
!r, !a: !r - repr(), !a - ascii() for unambiguous logs. Eliminates ambiguities in the output of objects:path = "/var/data/config.yaml"
print(f"{path!r} {path!a}") # repr and ascii()
n = 42
print(f"{n:08d}") # → #00000042
len():data = {"user": "Ivan", "items": [1, 2, 3]}
print(f"{data['user']}=», items={data['items']}")
print(f"len(data['items'])={len(data['items'])}")
