Overloading Operator Python

Pemrograman Berorientasi Objek Tingkat Menengah di Python

Jake Roach

Data Engineer

Overloading operator perbandingan

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

  def __eq__(self, other):
      return self.name == other.name

Sesuaikan fungsi ==

Gunakan magic method __eq__()
Menerima self dan other
Mengembalikan nilai boolean

bryce = Person("Bryce")
orion = Person("Orion")
print(bryce == orion)

False

chuck = Person("Charles Carmichael")
charles = Person("Charles Carmichael")
print(chuck == charles)

True

Menambahkan dua objek

class Team:
  def __init__(self, team_members):
      self.team_members = team_members

# Create two Team objects, attempt to add them
rookies = Team(["Casey", "Emmitt"])
veterans = Team(["Mike", "Chuck"])
dream_team = rookies + veterans

Traceback (most recent call last):
  File "<stdin>", line 8, in <module>
TypeError: unsupported operand type(s) for +: 'Team' and 'Team'

Overloading operator +

class Team:
  def __init__(self, team_members):
    # team_members is a list of names
    self.team_members = team_members

  def __add__(self, other):
    # Adding Team objects creates a larger Team
    return Team(self.team_members + other.team_members)

Gunakan magic method __add__() untuk overload +
self dan other diteruskan ke __add__()
Buat objek Team baru dari team_members milik objek yang “ditambahkan”

Menambahkan dua objek

# Create two Team objects
rookies = Team(["Casey", "Emmitt"])
veterans = Team(["Mike", "Chuck"])

# Attempt to add these two Teams together
dream_team = rookies + veterans
print(type(dream_team))
print(dream_team.team_members)

Team
["Casey", "Emmitt", "Mike", "Chuck"]

Menggunakan + untuk membuat tipe objek baru

class Team:
  def __init__(self, team_members):
      self.team_members = team_members

class Employee:
  def __init__(self, name, title):
    self.name = name
    self.title = title

  def __add__(self, other):
    # Use the + operator to create a
    # Team with the name of each Employee
    return Team([self.name, other.name])

Bagaimana jika kita ingin membuat Team dari gabungan objek Employee?

__add__ diimplementasikan di kelas Employee
Membuat objek Team baru dari daftar nama Employee
Hasil penjumlahan dua objek Employee adalah satu Team

Menjumlahkan dua objek untuk membuat objek baru

# Create two Employee objects
anna = Employee("Anna", "Technical Specialist")
jeff = Employee("Jeffrey", "Musician")

# Now, attempt to add these together to create a team
audio_team = anna + jeff
print(type(audio_team))
print(audio_team.team_members)

Team
["Anna", "Jeffrey"]

Overloading operator lain

Operator	Magic Method	Jenis Operator
-	`__sub__`	Aritmetika
!=	`__ne__`	Perbandingan
<	`__lt__`	Perbandingan
>	`__gt__`	Perbandingan
+=	`__iadd__`	Penugasan
and	`__and__`	Logika
in	`__contains__`	Keanggotaan
is	`__is__`	Identitas

... Dan masih banyak lagi!

Ayo berlatih!

Pemrograman Berorientasi Objek Tingkat Menengah di Python