Python中命名元组Namedtuple的使用详解

from collections import namedtuple
# Declaring namedtuple()
Student = namedtuple('Student', ['name', 'age', 'DOB'])
# Adding values
S = Student('Nandini', '19', '2541997')
# Access using index
print("The Student age using index is : ", end="")
print(S[1])
# Access using name
print("The Student name using keyname is : ", end="")
print(S.name)

# Python code to demonstrate namedtuple() and
# Access by name, index and getattr()
import collections
# Declaring namedtuple()
Student = collections.namedtuple('Student', ['name', 'age', 'DOB'])
# Adding values
S = Student('Nandini', '19', '2541997')
# Access using index
print("The Student age using index is : ", end="")
print(S[1])
# Access using name
print("The Student name using keyname is : ", end="")
print(S.name)
# Access using getattr()
print("The Student DOB using getattr() is : ", end="")
print(getattr(S, 'DOB'))

# Python code to demonstrate namedtuple() and
# _make(), _asdict() and "**" operator
# importing "collections" for namedtuple()
import collections
# Declaring namedtuple()
Student = collections.namedtuple('Student',
								['name', 'age', 'DOB'])
# Adding values
S = Student('Nandini', '19', '2541997')
# initializing iterable
li = ['Manjeet', '19', '411997']
# initializing dict
di = {'name': "Nikhil", 'age': 19, 'DOB': '1391997'}
# using _make() to return namedtuple()
print("The namedtuple instance using iterable is : ")
print(Student._make(li))
# using _asdict() to return an OrderedDict()
print("The OrderedDict instance using namedtuple is : ")
print(S._asdict())
# using ** operator to return namedtuple from dictionary
print("The namedtuple instance from dict is : ")
print(Student(**di))

# Python code to demonstrate namedtuple() and
# _fields and _replace()
import collections
# Declaring namedtuple()
Student = collections.namedtuple('Student', ['name', 'age', 'DOB'])
# Adding values
S = Student('Nandini', '19', '2541997')
# using _fields to display all the keynames of namedtuple()
print("All the fields of students are : ")
print(S._fields)
# ._replace returns a new namedtuple, it does not modify the original
print("returns a new namedtuple : ")
print(S._replace(name='Manjeet'))
# original namedtuple
print(S)
# Student.__new__ returns a new instance of Student(name,age,DOB)
print(Student.__new__(Student,'Himesh','19','26082003'))
H=Student('Himesh','19','26082003')
# .__getnewargs__ returns the named tuple as a plain tuple
print(H.__getnewargs__())

from collections import namedtuple
Point = namedtuple('Point', ['x', 'y'])
p = Point(x=1, y=2)
print(p.x, p.y) # Output: 1 2