[英]Python Pandas Calculate Number of values in columns for each row and put it in columns
[英]Calculate nonzeros percentage for specific columns and each row in Pandas
如果我有以下数据框:
df = pd.DataFrame({'name':['john','mary','peter','jeff','bill','lisa','jose'], 'gender':['M','F','M','M','M','F','M'],'state':['california','dc','california','dc','california','texas','texas'],'num_children':[2,0,0,3,2,1,4],'num_pets':[5,1,0,5,2,2,3]})
name gender state num_children num_pets
0 john M california 2 5
1 mary F dc 0 1
2 peter M california 0 0
3 jeff M dc 3 5
4 bill M california 2 2
5 lisa F texas 1 2
6 jose M texas 4 3
我想创建一个新的行和列pct.
获取num_children
和num_pets
列中零值的百分比预期输出:
name gender state num_children num_pets pct.
0 pct. 28.6% 14.3%
1 john M california 2 5 0%
2 mary F dc 0 1 50%
3 peter M california 0 0 100%
4 jeff M dc 3 5 0%
5 bill M california 2 2 0%
6 lisa F texas 1 2 0%
7 jose M texas 4 3 0%
我已经计算出目标列每一行的零百分比:
df['pct'] = df[['num_children', 'num_pets']].astype(bool).sum(axis=1)/2
df['pct.'] = 1-df['pct']
del df['pct']
df['pct.'] = pd.Series(["{0:.0f}%".format(val * 100) for val in df['pct.']], index = df.index)
name gender state num_children num_pets pct.
0 john M california 2 5 0%
1 mary F dc 0 1 50%
2 peter M california 0 0 100%
3 jeff M dc 3 5 0%
4 bill M california 2 2 0%
5 lisa F texas 1 2 0%
6 jose M texas 4 3 0%
但我不知道如何在pct
行下面插入结果。 作为预期的输出,请帮助我以更多的Python方式获得预期的结果。 谢谢。
df[['num_children', 'num_pets']].astype(bool).sum(axis=0)/len(df.num_children)
Out[153]:
num_children 0.714286
num_pets 0.857143
dtype: float64
更新:同样的事情,但是为了求和,非常感谢@jezrael:
df['sums'] = df[['num_children', 'num_pets']].sum(axis=1)
df1 = (df[['num_children', 'num_pets']].sum()
.to_frame()
.T
.assign(name='sums'))
df = pd.concat([df1.reindex(columns=df.columns, fill_value=''), df],
ignore_index=True, sort=False)
print (df)
name gender state num_children num_pets sums
0 sums 12 18
1 john M california 2 5 7
2 mary F dc 0 1 1
3 peter M california 0 0 0
4 jeff M dc 3 5 8
5 bill M california 2 2 4
6 lisa F texas 1 2 3
7 jose M texas 4 3 7
通过比较DataFrame.eq
0
值,可以将mean
与布尔值掩码DataFrame.eq
,因为sum/len=mean
按定义,乘以100
并用apply
加上百分比:
s = df[['num_children', 'num_pets']].eq(0).mean(axis=1)
df['pct'] = s.mul(100).apply("{0:.0f}%".format)
对于第一行, DataFrame
使用与原始列和concat
相同的列创建新的DataFrame
:
df1 = (df[['num_children', 'num_pets']].eq(0)
.mean()
.mul(100)
.apply("{0:.1f}%".format)
.to_frame()
.T
.assign(name='pct.'))
df = pd.concat([df1.reindex(columns=df.columns, fill_value=''), df],
ignore_index=True, sort=False)
print (df)
name gender state num_children num_pets pct
0 pct. 28.6% 14.3%
1 john M california 2 5 0%
2 mary F dc 0 1 50%
3 peter M california 0 0 100%
4 jeff M dc 3 5 0%
5 bill M california 2 2 0%
6 lisa F texas 1 2 0%
7 jose M texas 4 3 0%
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