blocks|key|997678|text|除非非常需要创建乱七八糟的变量名，否则我只会使用字典，在字典中可以动态创建键名称并为每个键关联一个值。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|997679|a+=+{}
k+=+0
while+k+<+10:
++++#+dynamically+create+key
++++key+=+...
++++#+calculate+value
++++value+=+...
++++a[key]+=+value+
++++k+%2B=+1|code-block|syntax|javascript|997680|在新的collections+module中也有一些有趣的数据结构可能适用。|offset|length|style|CODE|997681|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.python.org/library/collections.html^0|0|0|3|B|3|I|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@$I|X|J|Y|K|L]]|9|@$I|Z|J|10|1|11]]|A|$]]|$1|M|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

Unless there is an overwhelming need to create a mess of variable names, I would just use a dictionary, where you can dynamically create the key names and associate a value to each.
<pre><code>a = {}
k = 0
while k &lt; 10:
 # dynamically create key
 key = ...
 # calculate value
 value = ...
 a[key] = value 
 k += 1
</code></pre>
There are also some interesting data structures in the new <a href="https://docs.python.org/library/collections.html" rel="noreferrer"><code>collections</code> module</a> that might be applicable.

blocks|key|783400|text|globals()返回模块变量的字典。您可以通过在该字典上创建一个键来创建一个新变量：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|783401|#+By+default,+a+module+has+some+hidden+variables+defined
print({k:+v+for+k,+v+in+globals().items()+if+not+k.startswith("__")})

for+i+in+range(1,+11):
++++globals()[f"my_variable_{i}"]+=+i

print()
print(my_variable_1)
print(my_variable_2)
#+and+so+on

print()
print({k:+v+for+k,+v+in+globals().items()+if+not+k.startswith("__")})|code-block|syntax|javascript|783402|结果：|783403|{}

1
2

{'i':+10,+'my_variable_1':+1,+'my_variable_2':+2,+'my_variable_3':+3,+'my_variable_4':+4,+'my_variable_5':+5,+'my_variable_6':+6,+'my_variable_7':+7,+'my_variable_8':+8,+'my_variable_9':+9,+'my_variable_10':+10}|783404|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.python.org/library/functions.html#globals^0|0|9|0|9|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|13|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|14|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

<a href="https://docs.python.org/library/functions.html#globals" rel="noreferrer"><code>globals()</code></a> returns a dictionary of the module's variables. You can create a new variable by creating a key on that dictionary:
<pre class="lang-py prettyprint-override"><code># By default, a module has some hidden variables defined
print({k: v for k, v in globals().items() if not k.startswith(&quot;__&quot;)})

for i in range(1, 11):
 globals()[f&quot;my_variable_{i}&quot;] = i

print()
print(my_variable_1)
print(my_variable_2)
# and so on

print()
print({k: v for k, v in globals().items() if not k.startswith(&quot;__&quot;)})
</code></pre>
Result:
<pre class="lang-none prettyprint-override"><code>{}

1
2

{'i': 10, 'my_variable_1': 1, 'my_variable_2': 2, 'my_variable_3': 3, 'my_variable_4': 4, 'my_variable_5': 5, 'my_variable_6': 6, 'my_variable_7': 7, 'my_variable_8': 8, 'my_variable_9': 9, 'my_variable_10': 10}
</code></pre>

blocks|key|783529|text|使用exec()方法运行任意代码。例如，假设您有一个字典，并且您希望将每个键转换为具有其原始字典值的变量，您可以执行以下操作：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|783530|>>>+c+=+{"one":+1,+"two":+2}
>>>+for+k,+v+in+c.items():
...+++++exec(f"{k}+=+{v}")
...+
>>>+one
1
>>>+two
2|code-block|syntax|javascript|783531|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.python.org/library/functions.html#exec^0|2|6|2|6|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@$9|V|A|W|1|X]]|E|$]]|$1|F|3|G|5|H|7|Y|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

Use the <a href="https://docs.python.org/library/functions.html#exec" rel="noreferrer"><code>exec()</code></a> method to run arbitrary code. For example, say you have a dictionary and you want to turn each key into a variable with its original dictionary value, you can do the following:
<pre><code>&gt;&gt;&gt; c = {&quot;one&quot;: 1, &quot;two&quot;: 2}
&gt;&gt;&gt; for k, v in c.items():
... exec(f&quot;{k} = {v}&quot;)
... 
&gt;&gt;&gt; one
1
&gt;&gt;&gt; two
2
</code></pre>

blocks|key|997801|text|将内容填充到全局和/或本地名称空间中不是一个好主意。使用字典有点另类语言的味道……d['constant-key']+=+value看起来很笨拙。Python是面向对象的。用大师的话说：“名称空间是一个非常棒的主意--让我们做更多这样的事情吧！”|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|997802|如下所示：|997803|>>>+class+Record(object):
...+++++pass
...
>>>+r+=+Record()
>>>+r.foo+=+'oof'
>>>+setattr(r,+'bar',+'rab')
>>>+r.foo
'oof'
>>>+r.bar
'rab'
>>>+names+=+'id+description+price'.split()
>>>+values+=+[666,+'duct+tape',+3.45]
>>>+s+=+Record()
>>>+for+name,+value+in+zip(names,+values):
...+++++setattr(s,+name,+value)
...
>>>+s.__dict__+#+If+you+are+suffering+from+dict+withdrawal+symptoms
{'price':+3.45,+'id':+666,+'description':+'duct+tape'}
>>>|code-block|syntax|javascript|997804|entityMap^0|15|P|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|R|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|S|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|N|$]]

Stuffing things into the global and/or local namespaces is not a good idea. Using a dict is so some-other-language-ish ... <code>d['constant-key'] = value</code> just looks awkward. Python is OO. In the words of a master: """Namespaces are one honking great idea -- let's do more of those!"""

Like this:

<pre><code>&gt;&gt;&gt; class Record(object):
... pass
...
&gt;&gt;&gt; r = Record()
&gt;&gt;&gt; r.foo = 'oof'
&gt;&gt;&gt; setattr(r, 'bar', 'rab')
&gt;&gt;&gt; r.foo
'oof'
&gt;&gt;&gt; r.bar
'rab'
&gt;&gt;&gt; names = 'id description price'.split()
&gt;&gt;&gt; values = [666, 'duct tape', 3.45]
&gt;&gt;&gt; s = Record()
&gt;&gt;&gt; for name, value in zip(names, values):
... setattr(s, name, value)
...
&gt;&gt;&gt; s.__dict__ # If you are suffering from dict withdrawal symptoms
{'price': 3.45, 'id': 666, 'description': 'duct tape'}
&gt;&gt;&gt;
</code></pre>

blocks|key|783550|text|vars()['meta_anio_2012']+=+'translate'|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|783551|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>vars()['meta_anio_2012'] = 'translate'
</code></pre>

blocks|key|997986|text|Keyword+parameters允许您将变量从一个函数传递到另一个函数。通过这种方式，您可以将字典的键用作变量名(可以在while循环中填充)。调用字典时，只需在字典名称前面加上**即可。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|997987|#+create+a+dictionary
>>>+kwargs+=+{}
#+add+a+key+of+name+and+assign+it+a+value,+later+we'll+use+this+key+as+a+variable
>>>+kwargs['name']+=+'python'

#+an+example+function+to+use+the+variable
>>>+def+print_name(name):
...+++print+name

#+call+the+example+function
>>>+print_name(**kwargs)
python|code-block|syntax|javascript|997988|没有**，kwargs只是一本字典：|997989|>>>+print_name(kwargs)
{'name':+'python'}|997990|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.python.org/2/faq/programming.html#how-can-i-pass-optional-or-keyword-parameters-from-one-function-to-another^0|1Q|5|2J|2|0|I|0|0|0|2|2|5|6|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@$9|11|A|12|1|13]]|E|$]]|$1|F|3|G|5|H|7|14|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|15|8|@$9|16|A|17|B|C]|$9|18|A|19|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|1A|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|1B|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

<a href="https://docs.python.org/2/faq/programming.html#how-can-i-pass-optional-or-keyword-parameters-from-one-function-to-another" rel="noreferrer">Keyword parameters</a> allow you to pass variables from one function to another. In this way you can use the key of a dictionary as a variable name (which can be populated in your <code>while</code> loop). The dictionary name just needs to be preceded by <code>**</code> when it is called.

<pre><code># create a dictionary
&gt;&gt;&gt; kwargs = {}
# add a key of name and assign it a value, later we'll use this key as a variable
&gt;&gt;&gt; kwargs['name'] = 'python'

# an example function to use the variable
&gt;&gt;&gt; def print_name(name):
... print name

# call the example function
&gt;&gt;&gt; print_name(**kwargs)
python
</code></pre>

Without <code>**</code>, <code>kwargs</code> is just a dictionary:

<pre><code>&gt;&gt;&gt; print_name(kwargs)
{'name': 'python'}
</code></pre>

blocks|key|997860|text|对于free-dom：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|997861|import+random

alphabet+=+tuple('abcdefghijklmnopqrstuvwxyz')

globkeys+=+globals().keys()
globkeys.append('globkeys')+#+because+name+'globkeys'+is+now+also+in+globals()

print+'globkeys==',globkeys
print
print+"globals().keys()==",globals().keys()

for+i+in+xrange(8):
++++globals()[''.join(random.sample(alphabet,random.randint(3,26)))]+=+random.choice(alphabet)
del+i

newnames+=+[+x+for+x+in+globals().keys()+if+x+not+in+globkeys+]
print
print+'newnames==',newnames

print
print+"globals().keys()==",globals().keys()

print
print+'\n'.join(repr((u,globals()[u]))+for+u+in+newnames)|code-block|syntax|javascript|997862|结果|997863|globkeys==+['__builtins__',+'alphabet',+'random',+'__package__',+'__name__',+'__doc__',+'globkeys']

globals().keys()==+['__builtins__',+'alphabet',+'random',+'__package__',+'__name__',+'globkeys',+'__doc__']

newnames==+['fztkebyrdwcigsmulnoaph',+'umkfcvztleoij',+'kbutmzfgpcdqanrivwsxly',+'lxzmaysuornvdpjqfetbchgik',+'wznptbyermclfdghqxjvki',+'lwg',+'vsolxgkz',+'yobtlkqh']

globals().keys()==+['fztkebyrdwcigsmulnoaph',+'umkfcvztleoij',+'newnames',+'kbutmzfgpcdqanrivwsxly',+'__builtins__',+'alphabet',+'random',+'lxzmaysuornvdpjqfetbchgik',+'__package__',+'wznptbyermclfdghqxjvki',+'lwg',+'x',+'vsolxgkz',+'__name__',+'globkeys',+'__doc__',+'yobtlkqh']

('fztkebyrdwcigsmulnoaph',+'t')
('umkfcvztleoij',+'p')
('kbutmzfgpcdqanrivwsxly',+'a')
('lxzmaysuornvdpjqfetbchgik',+'n')
('wznptbyermclfdghqxjvki',+'t')
('lwg',+'j')
('vsolxgkz',+'w')
('yobtlkqh',+'c')|997864|另一种方式：|997865|import+random

pool_of_names+=+[]
for+i+in+xrange(1000):
++++v+=+'LXM'%2Bstr(random.randrange(10,100000))
++++if+v+not+in+globals():
++++++++pool_of_names.append(v)

alphabet+=+'abcdefghijklmnopqrstuvwxyz'+

print+'globals().keys()==',globals().keys()

print
for+j+in+xrange(8):
++++globals()[pool_of_names[j]]+=+random.choice(alphabet)
newnames+=+pool_of_names[0:j%2B1]

print
print+'globals().keys()==',globals().keys()

print
print+'\n'.join(repr((u,globals()[u]))+for+u+in+newnames)|997866|结果：|997867|globals().keys()==+['__builtins__',+'alphabet',+'random',+'__package__',+'i',+'v',+'__name__',+'__doc__',+'pool_of_names']


globals().keys()==+['LXM7646',+'random',+'newnames',+'LXM95826',+'pool_of_names',+'LXM66380',+'alphabet',+'LXM84070',+'__package__',+'LXM8644',+'__doc__',+'LXM33579',+'__builtins__',+'__name__',+'LXM58418',+'i',+'j',+'LXM24703',+'v']

('LXM66380',+'v')
('LXM7646',+'a')
('LXM8644',+'m')
('LXM24703',+'r')
('LXM58418',+'g')
('LXM84070',+'c')
('LXM95826',+'e')
('LXM33579',+'j')|997868|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

For free-dom:

<pre><code>import random

alphabet = tuple('abcdefghijklmnopqrstuvwxyz')

globkeys = globals().keys()
globkeys.append('globkeys') # because name 'globkeys' is now also in globals()

print 'globkeys==',globkeys
print
print "globals().keys()==",globals().keys()

for i in xrange(8):
 globals()[''.join(random.sample(alphabet,random.randint(3,26)))] = random.choice(alphabet)
del i

newnames = [ x for x in globals().keys() if x not in globkeys ]
print
print 'newnames==',newnames

print
print "globals().keys()==",globals().keys()

print
print '\n'.join(repr((u,globals()[u])) for u in newnames)
</code></pre>

Result

<pre><code>globkeys== ['__builtins__', 'alphabet', 'random', '__package__', '__name__', '__doc__', 'globkeys']

globals().keys()== ['__builtins__', 'alphabet', 'random', '__package__', '__name__', 'globkeys', '__doc__']

newnames== ['fztkebyrdwcigsmulnoaph', 'umkfcvztleoij', 'kbutmzfgpcdqanrivwsxly', 'lxzmaysuornvdpjqfetbchgik', 'wznptbyermclfdghqxjvki', 'lwg', 'vsolxgkz', 'yobtlkqh']

globals().keys()== ['fztkebyrdwcigsmulnoaph', 'umkfcvztleoij', 'newnames', 'kbutmzfgpcdqanrivwsxly', '__builtins__', 'alphabet', 'random', 'lxzmaysuornvdpjqfetbchgik', '__package__', 'wznptbyermclfdghqxjvki', 'lwg', 'x', 'vsolxgkz', '__name__', 'globkeys', '__doc__', 'yobtlkqh']

('fztkebyrdwcigsmulnoaph', 't')
('umkfcvztleoij', 'p')
('kbutmzfgpcdqanrivwsxly', 'a')
('lxzmaysuornvdpjqfetbchgik', 'n')
('wznptbyermclfdghqxjvki', 't')
('lwg', 'j')
('vsolxgkz', 'w')
('yobtlkqh', 'c')
</code></pre>

Another way:

<pre><code>import random

pool_of_names = []
for i in xrange(1000):
 v = 'LXM'+str(random.randrange(10,100000))
 if v not in globals():
 pool_of_names.append(v)

alphabet = 'abcdefghijklmnopqrstuvwxyz' 

print 'globals().keys()==',globals().keys()

print
for j in xrange(8):
 globals()[pool_of_names[j]] = random.choice(alphabet)
newnames = pool_of_names[0:j+1]

print
print 'globals().keys()==',globals().keys()

print
print '\n'.join(repr((u,globals()[u])) for u in newnames)
</code></pre>

result:

<pre><code>globals().keys()== ['__builtins__', 'alphabet', 'random', '__package__', 'i', 'v', '__name__', '__doc__', 'pool_of_names']


globals().keys()== ['LXM7646', 'random', 'newnames', 'LXM95826', 'pool_of_names', 'LXM66380', 'alphabet', 'LXM84070', '__package__', 'LXM8644', '__doc__', 'LXM33579', '__builtins__', '__name__', 'LXM58418', 'i', 'j', 'LXM24703', 'v']

('LXM66380', 'v')
('LXM7646', 'a')
('LXM8644', 'm')
('LXM24703', 'r')
('LXM58418', 'g')
('LXM84070', 'c')
('LXM95826', 'e')
('LXM33579', 'j')
</code></pre>

I want to create variables dynamically in Python. Does anyone have any creative means of doing this?

How can you dynamically create variables?

数据结构

Python

我想在Python中动态创建变量。有没有人有任何创造性的方法来做这件事？

问如何动态创建变量？
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回答 7

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