2019年4月11日 星期四

Python Tip - Examples of initialize variables with sequence number in different ways

Purpose

It is used to collect sample code for python's coding tips of initialization variables.

A. Variables with constants

test_init_vars.py

#!/usr/bin/env python

a=0
b=1
c=2
d=3
e=4
f=5
print(a, b, c, d, e, f)

B. Use range()

test_init_vars_by_range.py

#!/usr/bin/env python

a, b, c, d, e, f = range(6)

print(a, b, c, d, e, f)

C. Use enum since python 3.4 supported

test_init_vars_by_enum.py

#!/usr/bin/env python3.6

from enum import IntEnum,auto

class Vars(IntEnum):
    a=0
    b=auto()
    c=auto()
    d=auto()
    e=auto()
    f=auto()

print("{}, {}, {}, {}, {}, {}".format(Vars.a, Vars.b, Vars.c, Vars.d, Vars.e, Vars.f))

Result

$ python2.7 test_init_vars.py
(0, 1, 2, 3, 4, 5)
$ python3.6 test_init_vars.py
0 1 2 3 4 5

$ python2.7 test_init_vars_by_range.py
(0, 1, 2, 3, 4, 5)
$ python3.6 test_init_vars_by_range.py
0 1 2 3 4 5

$ python2.7 test_init_vars_by_enum.py
Traceback (most recent call last):
  File "test_init_vars_by_enum.py", line 3, in
    from enum import IntEnum,auto
ImportError: cannot import name auto

$ python3.6 test_init_vars_by_enum.py
0, 1, 2, 3, 4, 5

References