我可以更加简洁地表达命名的Python字符串参数吗？

Question

我知道有两种方法可以在字符串中包含命名参数:

name = "Mary"
pet = "lamb"

# option 1
message = "%(name)s had a little %(pet)s" % {"name": name, "pet": pet}
print(message)

# option 2
message = "{name} had a little {pet}"
message.format(name = name, pet = pet)
print(message)
# I'm not actually sure if `name = name` works, usually these are different

我认为其中任何一个都不具备可读性.有没有办法减少重复变量名称的次数？

字符串参数的命名(非空)非常重要,这样:

• 它们可以在字符串中重复: %(name)s %(name)s quite contrary how does your %(pet)s grow?
• 在翻译字符串时它们是可见的: %(name)s alikuwa kidogo %(pet)s

Answer 1

用一个对象:

person.name = 'foo'
person.age = 12

你可以做:

print '{name} is {age} old'.format(**person.__dict__)

用字典:

a = {'name': 'foo', age: 12}
print '{name} is {age} old'.format(**a)

使用list/tuple/set/namedtuple:

a = [1,2,3]
b = (1,2,3)
c = set([1,2,3,1])

from collections import namedtuple
Foo = namedtuple('Foo', 'x y z')
foo = Foo(1,2,3)
print '{} {} {}'.format(*foo)


print '{} {} {}'.format(*a)
print '{} {} {}'.format(*b)
print '{} {} {}'.format(*c)
print '{} {} {}'.format(*foo)

但是,namedtuple它不仅仅是一个元组,它也是一个对象,所以你也可以这样做:

print '{x} {z} {y}'.format(**foo._asdict())

列表可能会更长,我会停在这里,但现在你明白了......