擅长:python、mysql、java
<p>这就是你想要的吗?你知道吗</p>
<pre><code>L = [{'town':'A', 'x':12, 'y':13},{'town':'B', 'x':100, 'y':43},{'town':'C', 'x':19, 'y':5}]
X, Y = 2, 3
mxr = 30
def calculateRange(x1, x2, y1, y2):
return round( ((x1-x2)**2 + (y1-y2)**2)**.5, 1 )
R = []
for e in L:
r = calculateRange(e['x'], X, e['y'], Y)
if r <= mxr:
e['r'] = r
R.append(e)
print R
# [{'town': 'A', 'x': 12, 'r': 14.1, 'y': 13}, {'town': 'C', 'x': 19, 'r': 17.1, 'y': 5}]
</code></pre>