I want to get interval margins of a column with pandas intervals and write them in columns 'left', 'right'. Iterrows does not work (documentation says it would not be use for writing data) and, anyway it would not be the better solution.
import pandas as pd
i1 = pd.Interval(left=85, right=94)
i2 = pd.Interval(left=95, right=104)
i3 = pd.Interval(left=105, right=114)
i4 = pd.Interval(left=115, right=124)
i5 = pd.Interval(left=125, right=134)
i6 = pd.Interval(left=135, right=144)
i7 = pd.Interval(left=145, right=154)
i8 = pd.Interval(left=155, right=164)
i9 = pd.Interval(left=165, right=174)
data = pd.DataFrame(
{
"intervals":[i1,i2,i3,i4,i5,i6,i7,i8,i9],
"left" :[0,0,0,0,0,0,0,0,0],
"right" :[0,0,0,0,0,0,0,0,0]
},
index=[0,1,2,3,4,5,6,7,8]
)
#this is not working (has no effect):
for index, row in data.iterrows():
print(row.intervals.left, row.intervals.right)
row.left = row.intervals.left
row.right = row.intervals.right
How can we do something like:
data['left']=data['intervals'].left
data['right']=data['intervals'].right
Thanks!
Create an pandas.IntervalIndex from your intervals. You can then access the .left and .right attributes.
import pandas as pd
idx = pd.IntervalIndex([i1, i2, i3, i4, i5, i6, i7, i8, i9])
pd.DataFrame({'intervals': idx, 'left': idx.left, 'right': idx.right})
intervals left right
0 (85, 94] 85 94
1 (95, 104] 95 104
2 (105, 114] 105 114
3 (115, 124] 115 124
4 (125, 134] 125 134
5 (135, 144] 135 144
6 (145, 154] 145 154
7 (155, 164] 155 164
8 (165, 174] 165 174
Another option is using map and operator.attrgetter (look ma, no lambda...):
from operator import attrgetter
df['left'] = df['intervals'].map(attrgetter('left'))
df['right'] = df['intervals'].map(attrgetter('right'))
df
intervals left right
0 (85, 94] 85 94
1 (95, 104] 95 104
2 (105, 114] 105 114
3 (115, 124] 115 124
4 (125, 134] 125 134
5 (135, 144] 135 144
6 (145, 154] 145 154
7 (155, 164] 155 164
8 (165, 174] 165 174