在Python中格式化多行dict的正确方法是什么？

在Python中，我想在代码中编写一个多行dict。有几种方法可以格式化它。以下是我能想到的几个：

我知道上述任何一种语法都是正确的，但我假设Python dict有一种首选的缩进和换行样式。这是什么

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

根据我在教程和其他方面的经验，第2项似乎总是首选，但这是个人的首选，而不是其他任何东西。

我使用#3。长列表、元组等也一样。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'),
    ],
}

类似地，这里是我在不引入任何空格的情况下包含大字符串的首选方法（如使用三引号多行字符串）：

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由于您的键是字符串，而且我们讨论的是可读性，因此我更喜欢：

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

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一般来说，您不会在最后一个条目后包含逗号，但Python会为您更正。

首先，正如Steven Rumbalski所说，“PEP8不会解决这个问题”，因此这是个人偏好的问题

我将使用与您的格式3相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()

---

通常，如果您有大型python对象，则很难格式化它们。我个人更喜欢使用一些工具

---

这是一个可以立即将您的数据转换为可自定义样式的方法。

对于1和2：括号内没有空格，请参见PEP 8。我想说的是，在pythons pprint模块中，它使用了您的第一个示例，括号内没有空格。您是否可以提供一些参考，我很难找到关于这方面的权威来源。（我同意你的看法）。不要告诉他，但那个用户不知道他在说什么；更严重的是，我也找不到“权威”的参考资料。如果我这样做了，我会让你知道的！也许有人应该联系Guido。这符合PEP 8:。缩进部分底部有一些列表示例。您的“嵌套”示例语法无效。否！始终包含最后一个逗号，因此如果添加新的最后一个元素，则不必更改它前面的行。这是Python的一大优点：实用性胜过纯粹性。此外，这个答案并没有解决问题。不是每个人都喜欢尾随逗号，也许我们中的少数OCD患者更喜欢阅读更干净的代码。我喜欢在线评论。我的第一位编程教授（我已经编程多年了）坚持使用内联注释，但从未有效地解释过原因。你现在已经解释了一个我已经用了大约20年的方法。啊哈，谢谢。在编程方面，我们有相似的年龄、经验和“里程数”。那么，如果你已经在20年前开始了在线评论的实践（这真是令人印象深刻！），那么你为什么在大概10年前你还在大学的时候还需要教授的解释呢？只是好奇而已。：-）非常好的问题：）ATARI BASIC和GWbasic实际上是强制使用它的，它们是自顶向下的基于流水线的编译器。这是我在纸质杂志上阅读peter norton的基本（以及后来的ASM代码）时采用的。其间我学习了Turbo Pascal，但我已经学习了纸质杂志中的示例，并遵守了BASIC的限制。PEP8在某种程度上解决了这一问题，因为它建议不要在开口大括号后立即添加空格，因此OP中的选项1和2不适用。在定义KWARG时更喜欢不使用空格

c=function（a=1，b=2）

更“pythonic”。这并不能回答问题

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(",", "")))

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

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

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()

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(",", "")))