Python Pandas Dataframe - Where Condition Example

Here is an example on using Where condition on pandas dataframe.
Census data used as source.

Use Case : 

• Read Population data for state of California from "censusdata.ire.org" URL.
• Get Counties with population more than 1000000.

Syntax : 

DataFrame.where()

Main Parameters :

condition : 

     Condition should return boolean.


inplace :

    Whether to perform the operation in place

•  

raise_on_error :

•     Raise error on invalid data types

Sample Code

import pandas as pd
df = pd.read_csv("http://censusdata.ire.org/06/all_050_in_06.P1.csv")
df = df[["NAME","POP100"]]
df.where(df["POP100"] > 1000000).dropna(how='all')

Sample Output