Python pandas How to pick up certain values by internal numbering?
Question:
I have a dataframe that looks like this:
Answers all_answers Score
0 0.0 0 72
1 0.0 0 73
2 0.0 0 74
3 1.0 1 1
4 -1.0 1 2
5 1.0 1 3
6 -1.0 1 4
7 1.0 1 5
8 0.0 0 1
9 0.0 0 2
10 -1.0 1 1
11 0.0 0 1
12 0.0 0 2
13 1.0 1 1
14 0.0 0 1
15 0.0 0 2
16 1.0 1 1
The first column is a signal that the sign has changed in the calculation flow
The second one is I just removed the minus from the first one
The third is an internal account for the second column – how much was one and how much was zero
I want to add a fourth column to it that would show me only those units that went in a row for example 5 times while observing the sign of the first column.
To get something like this
Answers all_answers Score New
0 0.0 0 72 0
1 0.0 0 73 0
2 0.0 0 74 0
3 1.0 1 1 1
4 -1.0 1 2 -1
5 1.0 1 3 1
6 -1.0 1 4 -1
7 1.0 1 5 1
8 0.0 0 1 0
9 0.0 0 2 0
10 -1.0 1 1 0
11 0.0 0 1 0
12 0.0 0 2 0
13 1.0 1 1 0
14 0.0 0 1 0
15 0.0 0 2 0
16 1.0 1 1 0
17 0.0 0 1 0
Is it possible to do this by Pandas ?
Answers:
You can use:
# group by consecutive 0/1
g = df['all_answers'].ne(df['all_answers'].shift()).cumsum()
# get size of each group and compare to threshold
m = df.groupby(g)['all_answers'].transform('size').ge(5)
# mask small groups
df['New'] = df['Answers'].where(m, 0)
Output:
Answers all_answers Score New
0 0.0 0 72 0.0
1 0.0 0 73 0.0
2 0.0 0 74 0.0
3 1.0 1 1 1.0
4 -1.0 1 2 -1.0
5 1.0 1 3 1.0
6 -1.0 1 4 -1.0
7 1.0 1 5 1.0
8 0.0 0 1 0.0
9 0.0 0 2 0.0
10 -1.0 1 1 0.0
11 0.0 0 1 0.0
12 0.0 0 2 0.0
13 1.0 1 1 0.0
14 0.0 0 1 0.0
15 0.0 0 2 0.0
16 1.0 1 1 0.0
A faster way (with regex):
import pandas as pd
import re
def repl5(m):
return '5' * len(m.group())
s = df['all_answers'].astype(str).str.cat()
d = re.sub('(?:1{5,})', repl5, s)
d = [x=='5' for x in list(d)]
df['New'] = df['Answers'].where(d, 0.0)
df
Output:
Answers all_answers Score New
0 0.0 0 72 0.0
1 0.0 0 73 0.0
2 0.0 0 74 0.0
3 1.0 1 1 1.0
4 -1.0 1 2 -1.0
5 1.0 1 3 1.0
6 -1.0 1 4 -1.0
7 1.0 1 5 1.0
8 0.0 0 1 0.0
9 0.0 0 2 0.0
10 -1.0 1 1 0.0
11 0.0 0 1 0.0
12 0.0 0 2 0.0
13 1.0 1 1 0.0
14 0.0 0 1 0.0
15 0.0 0 2 0.0
16 1.0 1 1 0.0
I have a dataframe that looks like this:
Answers all_answers Score
0 0.0 0 72
1 0.0 0 73
2 0.0 0 74
3 1.0 1 1
4 -1.0 1 2
5 1.0 1 3
6 -1.0 1 4
7 1.0 1 5
8 0.0 0 1
9 0.0 0 2
10 -1.0 1 1
11 0.0 0 1
12 0.0 0 2
13 1.0 1 1
14 0.0 0 1
15 0.0 0 2
16 1.0 1 1
The first column is a signal that the sign has changed in the calculation flow
The second one is I just removed the minus from the first one
The third is an internal account for the second column – how much was one and how much was zero
I want to add a fourth column to it that would show me only those units that went in a row for example 5 times while observing the sign of the first column.
To get something like this
Answers all_answers Score New
0 0.0 0 72 0
1 0.0 0 73 0
2 0.0 0 74 0
3 1.0 1 1 1
4 -1.0 1 2 -1
5 1.0 1 3 1
6 -1.0 1 4 -1
7 1.0 1 5 1
8 0.0 0 1 0
9 0.0 0 2 0
10 -1.0 1 1 0
11 0.0 0 1 0
12 0.0 0 2 0
13 1.0 1 1 0
14 0.0 0 1 0
15 0.0 0 2 0
16 1.0 1 1 0
17 0.0 0 1 0
Is it possible to do this by Pandas ?
You can use:
# group by consecutive 0/1
g = df['all_answers'].ne(df['all_answers'].shift()).cumsum()
# get size of each group and compare to threshold
m = df.groupby(g)['all_answers'].transform('size').ge(5)
# mask small groups
df['New'] = df['Answers'].where(m, 0)
Output:
Answers all_answers Score New
0 0.0 0 72 0.0
1 0.0 0 73 0.0
2 0.0 0 74 0.0
3 1.0 1 1 1.0
4 -1.0 1 2 -1.0
5 1.0 1 3 1.0
6 -1.0 1 4 -1.0
7 1.0 1 5 1.0
8 0.0 0 1 0.0
9 0.0 0 2 0.0
10 -1.0 1 1 0.0
11 0.0 0 1 0.0
12 0.0 0 2 0.0
13 1.0 1 1 0.0
14 0.0 0 1 0.0
15 0.0 0 2 0.0
16 1.0 1 1 0.0
A faster way (with regex):
import pandas as pd
import re
def repl5(m):
return '5' * len(m.group())
s = df['all_answers'].astype(str).str.cat()
d = re.sub('(?:1{5,})', repl5, s)
d = [x=='5' for x in list(d)]
df['New'] = df['Answers'].where(d, 0.0)
df
Output:
Answers all_answers Score New
0 0.0 0 72 0.0
1 0.0 0 73 0.0
2 0.0 0 74 0.0
3 1.0 1 1 1.0
4 -1.0 1 2 -1.0
5 1.0 1 3 1.0
6 -1.0 1 4 -1.0
7 1.0 1 5 1.0
8 0.0 0 1 0.0
9 0.0 0 2 0.0
10 -1.0 1 1 0.0
11 0.0 0 1 0.0
12 0.0 0 2 0.0
13 1.0 1 1 0.0
14 0.0 0 1 0.0
15 0.0 0 2 0.0
16 1.0 1 1 0.0