擅长:python、mysql、java
<p>您应该注意,当您的索引是唯一的时,即使是iloc也比hashmap慢2个数量级:</p>
<pre><code>df = pd.DataFrame(np.random.randint(0, 10**7, 10**5), columns=['a'])
%timeit df.iloc[random.randint(0,10**5)]
10000 loops, best of 3: 51.5 µs per loop
s = set(np.random.randint(0, 10**7, 10**5))
%timeit random.randint(0,10**7) in s
The slowest run took 9.70 times longer than the fastest. This could mean that an intermediate result is being cached.
1000000 loops, best of 3: 615 ns per loop
</code></pre>