问替换“？”时出错中的平均值(以数据为单位)

EN

vals = pd.to_numeric(df["normalized-losses"], errors='coerce')
df["normalized-losses"] = vals.fillna(vals.mean()) 
#data from jpp
print (df)
   normalized-losses
0                1.0
1                2.0
2                3.0
3                3.4
4                5.0
5                6.0
6                3.4

print (vals)
0    1.0
1    2.0
2    3.0
3    NaN
4    5.0
5    6.0
6    NaN
Name: normalized-losses, dtype: float64

print (vals.mean())
3.4

df['normalized-losses'] = df['normalized-losses'].replace('?',np.NaN)
df['normalized-losses'].fillna(df['normalized-losses'].mean())

df = pd.DataFrame({'A': [1, 2, 3, '?', 5, 6, '??']})

mean = pd.to_numeric(df['A'], errors='coerce').mean()
df['B'] = df['A'].replace('?', mean)

print(df)

    A    B
0   1    1
1   2    2
2   3    3
3   ?  3.4
4   5    5
5   6    6
6  ??   ??

nums = pd.to_numeric(df['A'], errors='coerce')
df['B'] = nums.fillna(nums.mean())

print(df)

    A    B
0   1  1.0
1   2  2.0
2   3  3.0
3   ?  3.4
4   5  5.0
5   6  6.0
6  ??  3.4