pandas Indexing and selecting data Slicing with labels


Example

When using labels, both the start and the stop are included in the results.

import pandas as pd
import numpy as np
np.random.seed(5)
df = pd.DataFrame(np.random.randint(100, size=(5, 5)), columns = list("ABCDE"), 
                  index = ["R" + str(i) for i in range(5)])

# Out: 
#      A   B   C   D   E
# R0  99  78  61  16  73
# R1   8  62  27  30  80
# R2   7  76  15  53  80
# R3  27  44  77  75  65
# R4  47  30  84  86  18

Rows R0 to R2:

df.loc['R0':'R2']
# Out: 
#      A   B   C   D   E
# R0   9  41  62   1  82
# R1  16  78   5  58   0
# R2  80   4  36  51  27

Notice how loc differs from iloc because iloc excludes the end index

df.loc['R0':'R2'] # rows labelled R0, R1, R2
# Out: 
#      A   B   C   D   E
# R0   9  41  62   1  82
# R1  16  78   5  58   0
# R2  80   4  36  51  27


# df.iloc[0:2] # rows indexed by 0, 1
#      A   B   C   D   E
# R0  99  78  61  16  73
# R1   8  62  27  30  80

Columns C to E:

df.loc[:, 'C':'E']
# Out: 
#      C   D   E
# R0  62   1  82
# R1   5  58   0
# R2  36  51  27
# R3  68  38  83
# R4   7  30  62