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Pandas: Default index and Set an Index

Pandas Indexing: Exercise-1 with Solution

Write a Pandas program to display the default index and set a column as an Index in a given dataframe.

Test Data:

0        s001     V  Alberto Franco     15/05/2002      35  street1   t1
1        s002     V    Gino Mcneill     17/05/2002      32  street2   t2
2        s003    VI     Ryan Parkes     16/02/1999      33  street3   t3
3        s001    VI    Eesha Hinton     25/09/1998      30  street1   t4
4        s002     V    Gino Mcneill     11/05/2002      31  street2   t5
5        s004    VI    David Parkes     15/09/1997      32  street4   t6

Sample Solution:

Python Code :

import pandas as pd
df = pd.DataFrame({
    'school_code': ['s001','s002','s003','s001','s002','s004'],
    'class': ['V', 'V', 'VI', 'VI', 'V', 'VI'],
    'name': ['Alberto Franco','Gino Mcneill','Ryan Parkes', 'Eesha Hinton', 'Gino Mcneill', 'David Parkes'],
    'date_Of_Birth': ['15/05/2002','17/05/2002','16/02/1999','25/09/1998','11/05/2002','15/09/1997'],
    'weight': [35, 32, 33, 30, 31, 32],
    'address': ['street1', 'street2', 'street3', 'street1', 'street2', 'street4'],
    't_id':['t1', 't2', 't3', 't4', 't5', 't6']})
print("Default Index:")
print(df.head(10))
print("\nschool_code as new Index:")
df1 = df.set_index('school_code')
print(df1)
print("\nt_id as new Index:")
df2 = df.set_index('t_id')
print(df2)

Sample Output:

Default Index:
  school_code class            name date_Of_Birth  weight  address t_id
0        s001     V  Alberto Franco    15/05/2002      35  street1   t1
1        s002     V    Gino Mcneill    17/05/2002      32  street2   t2
2        s003    VI     Ryan Parkes    16/02/1999      33  street3   t3
3        s001    VI    Eesha Hinton    25/09/1998      30  street1   t4
4        s002     V    Gino Mcneill    11/05/2002      31  street2   t5
5        s004    VI    David Parkes    15/09/1997      32  street4   t6

school_code as new Index:
            class            name date_Of_Birth  weight  address t_id
school_code                                                          
s001            V  Alberto Franco    15/05/2002      35  street1   t1
s002            V    Gino Mcneill    17/05/2002      32  street2   t2
s003           VI     Ryan Parkes    16/02/1999      33  street3   t3
s001           VI    Eesha Hinton    25/09/1998      30  street1   t4
s002            V    Gino Mcneill    11/05/2002      31  street2   t5
s004           VI    David Parkes    15/09/1997      32  street4   t6

t_id as new Index:
     school_code class            name date_Of_Birth  weight  address
t_id                                                                 
t1          s001     V  Alberto Franco    15/05/2002      35  street1
t2          s002     V    Gino Mcneill    17/05/2002      32  street2
t3          s003    VI     Ryan Parkes    16/02/1999      33  street3
t4          s001    VI    Eesha Hinton    25/09/1998      30  street1
t5          s002     V    Gino Mcneill    11/05/2002      31  street2
t6          s004    VI    David Parkes    15/09/1997      32  street4

Python Code Editor:


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Python: Tips of the Day

How to sort a Python dict by value

Example:

x1 = {'a': 5, 'b': 7, 'c': 9, 'd': 1}

sorted(x1.items(), key=lambda x: x[1])
[('d', 1), ('c', 9), ('b', 7), ('a', 5)]

# Or:

import operator
print(sorted(x1.items(), key=operator.itemgetter(1)))

Output:

[('d', 1), ('a', 5), ('b', 7), ('c', 9)]