<p>您可以使用掩蔽而不是使用循环</p>
<p>遮罩<code>[data3[max_index:] > 0]</code>和<code>[data3[:max_index] > 0]</code>等同于滑动<code>[max_index:(max_index+j)]</code>和<code>[(max_index-k):max_index]</code>,除非您不必费心自己寻找<code>j</code>和<code>k</code></p>
<pre><code>from contextlib import contextmanager
import numpy as np
import time
@contextmanager
def time_this_scope(name):
"""Handy context manager to time a portion of code."""
t0 = time.perf_counter()
yield
print(f"{name} took {time.perf_counter() - t0}s.")
# Preparing the data.
data1 = [x for x in range(0, 100000, 1)]
data2 = [x for x in range(100000, -1, -1)]
data3 = data1 + data2
max_index = np.where(data3 == np.amax(data3))[0][0]
# Comparing the performance of both methods.
with time_this_scope("method 1"):
j = 1
k = 0
while data3[max_index + j] > 0:
j += 1
while data3[max_index - k] > 0:
k += 1
summ1 = np.sum(data3[max_index:(max_index+j)])
summ2 = np.sum(data3[(max_index-k):max_index])
total_m1 = summ1 + summ2
with time_this_scope("method 2"):
data3 = np.array(data3)
summ1 = np.sum(data3[max_index:][data3[max_index:] > 0])
summ2 = np.sum(data3[:max_index][data3[:max_index] > 0])
total_m2 = summ1 + summ2
# Checking they do yield the same result.
print(total_m1 == total_m2)
>>> method 1 took 0.08157979999998588s.
>>> method 2 took 0.011274500000013177s.
>>> True
</code></pre>