擅长:python、mysql、java
<p>您的代码几乎是正确的,只是在<code>numer</code>中输入了一个拼写错误,并将结果存储在字典中:</p>
<pre><code>import pandas as pd
data = {'state': ['Rome', 'Venice', 'NY', 'Boston', 'London', 'Bristol'],
'year': [2000, 2001, 2002, 2001, 2003, 2003],
'number': [1.5, 1.7, 3.6, 2.4, 2.9, 3.2]}
dic = {
'it':['Rome', 'Venice'],
'UK':['London', 'Bristol'],
'US':['NY', 'Boston']
}
df = pd.DataFrame(data)
out = {}
for x, y in dic.items():
out[x] = df[df['state'].isin(y)].groupby(['year'], as_index=False)['number'].mean()
for country, df in out.items():
print(country)
print(df)
print('-' * 80)
</code></pre>
<p>印刷品:</p>
<pre><code>it
year number
0 2000 1.5
1 2001 1.7
UK
year number
0 2003 3.05
US
year number
0 2001 2.4
1 2002 3.6
</code></pre>