AttributeError: expanding_mean不起作用

Question

samples = {}
n = 30  
num_samples = 500  
for i in range(num_samples):
    samples[i] = population.sample(n).reset_index(drop=True)

samples = pd.DataFrame(samples)

df = pd.DataFrame({'estimated mean': pd.expanding_mean(samples.mean()),
                   'actual population mean': pd.Series(population.mean(), index=samples.columns)})
df.plot(ylim=(4.5, 6.5))

嗨，这段代码出现了一个错误，提示说模块 'pandas' 没有 'expanding_mean' 这个属性。请问正确的用法是什么？请帮帮我。

Answer 1

在新的Pandas版本中，expanding_mean这个函数已经被淘汰并且移除了。你可以用expanding().mean()来实现相同的功能。

import pandas as pd

samples = {}
n = 30  
num_samples = 500  
for i in range(num_samples):
    samples[i] = population.sample(n).reset_index(drop=True)

samples = pd.DataFrame(samples)

df = pd.DataFrame({'estimated mean': samples.expanding().mean().mean(axis=1),
                   'actual population mean': pd.Series(population.mean(), index=samples.columns)})
df.plot(ylim=(4.5, 6.5))