Python- Part 5

Here we go with next…Working with the mtcars dataset which we loaded before. Check the below screenshot for reference.

Selecting rows with condition

dst_n1 = dst.loc[(dst[‘cyl’] == 6) | (dst[‘mpg’] == 21)] Here we are selecting rows which has cyl = 6, and mpg = 21.

Output

Creating a new variable

import numpy as np
dst[‘NwVar’] = np.log2(dst[‘cyl’])

Output

New Variable named ‘NwVar’ has been created in last column.

Adding rows of data frame

import pandas as pd
df1 = pd.DataFrame({‘a’ : [1,2,3,4], ‘b’ : [4,5,6,7]})
df2 = pd.DataFrame({‘a’ : [7,8,9,2], ‘b’ : [3,7,8,9]})
df3 = df1.append(df2)

Output

Adding Columns

df3 = pd.concat([df1.reset_index(drop=True), df2], axis=1)

Output

Convert Variables

dt = mtcars dt[‘cyl’] = dst[‘cyl’].astype(object)

Output

check the below screenshots where variable ‘cyl’ is mentioned as ‘Int’ and after converting it shows as ‘Object’.

Convert Entire Dataframe

dst = dst.astype(object)

Convert numeric to categorical/binning

dst[‘mpgcat’] = np.where(dst[‘mpg’] > 20, ‘Low’, 0)

Sorting - ascending order

dst = dst.sort_values(‘cyl’, ascending = True)

Output

Sorting - descending order

dst = dst.sort_values(‘cyl’, ascending = False)

Output

Will end up here and see the next in next.