How to convert or change the data type of columns in Pandas dataframe ?

Changing the datatype of columns in pandas dataframe is very easy. Here I am using stype() function to perform the typecase operation.  Refer to the following example. The type conversion is happening in the line number 10 of the code.

 

You can add as many columns as you want to convert the data type or typecast. For example if you want to typecast the columns emp_id and salary, use the following syntax.

> df = df.astype({‘salary’:‘int’, ’emp_id’:’int’})

 

Bubble chart using Python

Bubble chart is one of the powerful and useful chart for representing data with three or four dimensions.

The position of the bubble is determined by the x & y axis values. These are the first two properties.

The size of the bubble can be controlled by the third property.

The colour of the bubble can be controlled by the fourth property.

A Sample program to create a bubble chart using the python library matplotlib is given below.

import matplotlib.pyplot as plot
import numpy as npy

# create some dummy data using numpy random function.
# Bubble charts are used to represent data with three or four dimensions.
# X axis can represent one property, Y can represent another property,
# The bubble size can represent another properly, the color of the bubble can represent another property.

x = npy.random.rand(50)
y = npy.random.rand(50)
z = npy.random.rand(50)
colors = npy.random.rand(50)
# use the scatter function
plot.scatter(x, y, s=z * 1000, c=colors)
plot.show()

Here we are generating some random data using numpy and plotting the bubble chart using matplotlib.

A sample output is given below.

bubblechart

Bubble Chart using Python