在Python中格式化多行dict的正确方法是什么?

时间:2011-06-17 15:35:52

标签: python indentation code-formatting multiline

在Python中,我想在我的代码中编写一个多行dict。有几种方法可以格式化它。以下是我能想到的一些内容:

  1. mydict = { "key1": 1,
               "key2": 2,
               "key3": 3, }
    
  2. mydict = { "key1": 1,
               "key2": 2,
               "key3": 3,
             }
    
  3. mydict = {
        "key1": 1,
        "key2": 2,
        "key3": 3,
    }
    
  4. 我知道上面的任何一个语法都是正确的,但我认为Python dicts有一个首选的缩进和换行符样式。它是什么?

    注意:这不是语法问题。以上所有(据我所知)有效的Python语句并且彼此等效。

7 个答案:

答案 0 :(得分:204)

我使用#3。对于长列表,元组等也是如此。它不需要在缩进之外添加任何额外的空格。一如既往,保持一致。

mydict = {
    "key1": 1,
    "key2": 2,
    "key3": 3,
}

mylist = [
    (1, 'hello'),
    (2, 'world'),
]

nested = {
    a: [
        (1, 'a'),
        (2, 'b'),
    ],
    b: [
        (3, 'c'),
        (4, 'd'),
    ],
}

同样,这是我首选的方法,即在不引入任何空格的情况下包含大字符串(如果使用三引号多行字符串,就会得到):

data = (
    "iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABG"
    "l0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAAEN"
    "xBRpFYmctaKCfwrBSCrRLuL3iEW6+EEUG8XvIVjYWNgJdhFjIX"
    "rz6pKtPB5e5rmq7tmxk+hqO34e1or0yXTGrj9sXGs1Ib73efh1"
    "AAAABJRU5ErkJggg=="
)

答案 1 :(得分:24)

首先,像Steven Rumbalski所说,“PEP8没有解决这个问题”,所以这是个人偏好的问题。

我会使用与格式3类似但不完全相同的格式。这是我的,为什么。

my_dictionary = { # Don't think dict(...) notation has more readability
    "key1": 1, # Indent by one press of TAB (i.e. 4 spaces)
    "key2": 2, # Same indentation scale as above
    "key3": 3, # Keep this final comma, so that future addition won't show up as 2-lines change in code diff
    } # My favorite: SAME indentation AS ABOVE, to emphasize this bracket is still part of the above code block!
the_next_line_of_code() # Otherwise the previous line would look like the begin of this part of code

bad_example = {
               "foo": "bar", # Don't do this. Unnecessary indentation wastes screen space
               "hello": "world" # Don't do this. Omitting the comma is not good.
} # You see? This line visually "joins" the next line when in a glance
the_next_line_of_code()

btw_this_is_a_function_with_long_name_or_with_lots_of_parameters(
    foo='hello world',  # So I put one parameter per line
    bar=123,  # And yeah, this extra comma here is harmless too;
              # I bet not many people knew/tried this.
              # Oh did I just show you how to write
              # multiple-line inline comment here?
              # Basically, same indentation forms a natural paragraph.
    ) # Indentation here. Same idea as the long dict case.
the_next_line_of_code()

# By the way, now you see how I prefer inline comment to document the very line.
# I think this inline style is more compact.
# Otherwise you will need extra blank line to split the comment and its code from others.

some_normal_code()

# hi this function is blah blah
some_code_need_extra_explanation()

some_normal_code()

答案 2 :(得分:9)

由于您的密钥是字符串,因为我们讨论的是可读性,所以我更喜欢:

mydict = dict(
    key1 = 1,
    key2 = 2,
    key3 = 3,
)

答案 3 :(得分:1)

通常,如果你有大型python对象,那么很难对它们进行格式化。我个人更喜欢使用一些工具。

这是python-beautifier - www.cleancss.com/python-beautify,可立即将您的数据转换为可自定义的样式。

答案 4 :(得分:0)

dict(rank = int(lst[0]),
                grade = str(lst[1]),
                channel=str(lst[2])),
                videos = float(lst[3].replace(",", " ")),
                subscribers = float(lst[4].replace(",", "")),
                views = float(lst[5].replace(",", "")))

答案 5 :(得分:-1)

根据我对教程的经验,以及其他东西,2号似乎总是首选,但它是个人偏好选择,而不是其他任何东西。

答案 6 :(得分:-6)

通常,您不会在最终条目后包含逗号,但Python会为您更正。