Python: Split pandas dataframe by range of values

Question

I have a simple dataframe in which I am trying to split into multiple groups based on whether the x column value falls within a range.

e.g. if I have:

print(df1)
  x
0 5
1 7.5
2 10
3 12.5
4 15

And wish to create a new dataframe, df2, of values of x which are within the range 7-13 (7 < x < 13)

print(df1)
  x   
0 5
4 15

print(df2)
  x
1 7.5
2 10
3 12.5

I have been able to split the dataframe based on a single value boolean e.g. ( x < 11), using the following - but have unable to develop this into a range of values.

thresh = 11
df2 = df1[df1['x'] < thresh]

print(df2)
  x
0 5
1 7.5
2 10

SeaBean · Accepted Answer · 2021-05-26 19:49:40Z

3

You can create a boolean mask for the range (7 < x < 13) by AND condition of (x > 7) and (x < 13). Then create df2 with this boolean mask. The remaining entries left in df1 being the negation of this boolean mask:

thresh_low = 7
thresh_high = 13
mask = (df1['x'] > thresh_low) & (df1['x'] < thresh_high)

df2 = df1[mask]
df1 = df1[~mask]

Result:

print(df2)

      x
1   7.5
2  10.0
3  12.5


print(df1)

      x
0   5.0
4  15.0

edited May 26, 2021 at 19:49

answered May 26, 2021 at 19:37

SeaBean

23.4k3 gold badges16 silver badges28 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

ALollz · Accepted Answer · 2021-05-26 19:40:53Z

1

You can use between to categorize whether the condition is met and then groupby to split based on your condition. Here I'll store the results in a dict

d = dict(tuple(df1.groupby(df1['x'].between(7, 13, inclusive=False))))

d[True]
#      x
#1   7.5
#2  10.0
#3  12.5

d[False]
#      x
#0   5.0
#4  15.0

Or with only two possible splits you can manually define the Boolean Series and then split based on it.

m = df1['x'].between(7, 13, inclusive=False)

df_in = df1[m]
df_out = df1[~m]

edited May 26, 2021 at 19:40

answered May 26, 2021 at 19:34

ALollz

59.7k7 gold badges73 silver badges97 bronze badges

Collectives™ on Stack Overflow

Python: Split pandas dataframe by range of values

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related