(dropna=False) # 查询每个独特数据值出现次数统计
s = pd.Series([1,2,3,3,4,np.nan,5,5,5,6,7])
s.value_counts(dropna=False...7.0
9 8.0
10 9.0
dtype: float64
df.apply(pd.Series.value_counts) # 查询数据框 (Data Frame) 中每个列的独特数据值出现次数统计...5.666667
4 7.000000
5 9.000000
6 9.000000
dtype: float64
s.astype(type) # 转换列的类型
s = pd.Series...()
A 0.128560
B 0.135905
C 0.167476
D 0.137062
E 0.050306
dtype: float64
df.median() #...()
A 0.272847
B 0.254870
C 0.258956
D 0.301168
E 0.295753
dtype: float64