擅长:python、mysql、java
<p>我猜你在找这样的东西:</p>
<pre><code>>>> lis = [
{'town':'A', 'x':12, 'y':13},
{'town':'B', 'x':100, 'y':43},
{'town':'C', 'x':19, 'y':5}
]
>>> x = 2
>>> y = 3
for dic in lis:
r = calculate(x,y,dic['x'],dic['y'])
dic['r'] = r
...
>>> lis = [x for x in lis if x['r'] <= mxr]
>>> lis
[{'y': 13, 'x': 12, 'town': 'A', 'r': 14.142135623730951}, {'y': 5, 'x': 19, 'town': 'C', 'r': 17.11724276862369}]
</code></pre>