blocks|key|1032520|text|第一个是大括号。否则，您会遇到带有奇数字符的密钥的一致性问题，如=。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1032521|#+Works+fine.
a+=+{
++++'a':+'value',
++++'b=c':+'value',
}

#+Eeep!+Breaks+if+trying+to+be+consistent.
b+=+dict(+
++++a='value',
++++b=c='value',
)|code-block|syntax|javascript|1032522|entityMap^0|W|1|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

<p>The first, curly braces. Otherwise, you run into consistency issues with keys that have odd characters in them, like <code>=</code>.</p>

<pre><code># Works fine.
a = {
    'a': 'value',
    'b=c': 'value',
}

# Eeep! Breaks if trying to be consistent.
b = dict( 
    a='value',
    b=c='value',
)
</code></pre>


blocks|key|1247644|text|大括号。将关键字参数传递到dict()中，尽管它在许多场景中都能很好地工作，但只有在键是有效的Python标识符时才能初始化映射。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1247645|这是可行的：|1247646|a+=+{'import':+'trade',+1:+7.8}|code-block|syntax|javascript|1247647|a+=+dict({'import':+'trade',+1:+7.8})|1247648|这是行不通的：|1247649|a+=+dict(import='trade',+1=7.8)|1247650|它将导致以下错误：|1247651|++++a+=+dict(import='trade',+1=7.8)
+++++++++++++%5E
SyntaxError:+invalid+syntax|1247652|entityMap^0|D|6|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|11|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|12|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|J|7|13|8|@]|D|@]|E|$K|L]]|$1|O|3|P|5|6|7|14|8|@]|D|@]|E|$]]|$1|Q|3|R|5|J|7|15|8|@]|D|@]|E|$K|L]]|$1|S|3|T|5|6|7|16|8|@]|D|@]|E|$]]|$1|U|3|V|5|J|7|17|8|@]|D|@]|E|$K|L]]|$1|W|3|-4|5|6|7|18|8|@]|D|@]|E|$]]]|X|$]]

<p>Curly braces. Passing keyword arguments into <code>dict()</code>, though it works beautifully in a lot of scenarios, can only initialize a map if the keys are valid Python identifiers.</p>
<h2>This works:</h2>
<pre><code>a = {'import': 'trade', 1: 7.8}
</code></pre>
<pre><code>a = dict({'import': 'trade', 1: 7.8})
</code></pre>
<h2>This won't work:</h2>
<pre><code>a = dict(import='trade', 1=7.8)
</code></pre>
<p>It will result in the following error:</p>
<pre><code>    a = dict(import='trade', 1=7.8)
             ^
SyntaxError: invalid syntax
</code></pre>


blocks|key|1032633|text|我认为第一个选项更好，因为您将以‘a’或‘’another‘的形式访问值。字典中的键是字符串，没有理由假装它们不是。对我来说，关键字语法乍看起来很聪明，但再看起来就晦涩难懂了。这只在你使用__dict__的时候才有意义，关键字稍后会变成属性，就像这样。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1032634|entityMap^0|2M|8|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

<p>I think the first option is better because you are going to access the values as a['a'] or a['another']. The keys in your dictionary are strings, and there is no reason to pretend they are not. To me the keyword syntax looks clever at first, but obscure at a second look. This only makes sense to me if you are working with <code>__dict__</code>, and the keywords are going to become attributes later, something like that.</p>


blocks|key|1032686|text|仅供参考，如果您需要向字典添加属性(附加到字典但不是键之一的内容)，那么您将需要第二种形式。在这种情况下，您可以使用具有任意字符的键来初始化字典，一次一个，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1032687|++++class+mydict(dict):+pass
++++a+=+mydict()++++++++
++++a["b=c"]+=+'value'
++++a.test+=+False|code-block|syntax|javascript|1032688|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>FYI, in case you need to add attributes to your dictionary (things that are attached to the dictionary, but are not one of the keys), then you'll need the second form.  In that case, you can initialize your dictionary with keys having arbitrary characters, one at a time, like so:</p>

<pre><code>    class mydict(dict): pass
    a = mydict()        
    a["b=c"] = 'value'
    a.test = False
</code></pre>


blocks|key|1247777|text|有时dict()是一个很好的选择：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1247778|a=dict(zip(['Mon','Tue','Wed','Thu','Fri'],+[x+for+x+in+range(1,+6)]))|code-block|syntax|javascript|1247779|entityMap^0|2|6|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

<p>Sometimes <code>dict()</code> is a good choice:</p>
<pre><code>a=dict(zip(['Mon','Tue','Wed','Thu','Fri'], [x for x in range(1, 6)]))
</code></pre>


<p>I'm putting in some effort to learn Python, and I am paying close attention to common coding standards.  This may seem like a pointlessly nit-picky question, but I am trying to focus on best-practices as I learn, so I don't have to unlearn any 'bad' habits later.</p>
<p>I see two common methods for initializing a dict:</p>
<pre><code>a = {
    'a': 'value',
    'another': 'value',
}

b = dict( 
    a='value',
    another='value',
)
</code></pre>
<p>Which is considered to be &quot;more pythonic&quot;?  Which do you use? Why?</p>


What is the preferred syntax for initializing a dict: curly brace literals {} or the dict() function?

Python

我正在努力学习Python，并密切关注常见的编码标准。这可能看起来像是一个毫无意义的吹毛求疵的问题，但我正试图在学习的过程中专注于最佳实践，这样我就不必在以后改掉任何“坏”习惯。我看到了两种常用的初始化dict的方法：a = {    'a': 'value',    'another': 'value',}b = d...

问初始化dict的首选语法是什么:花括号文字{}或dict()函数？
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问初始化dict的首选语法是什么:花括号文字{}或dict()函数？
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