NaN stands for Not A Number and is one of the common ways to represent the missing value in the data. It is a special floating-point value and cannot be converted to any other type than float. NaN value is one of the major problems in Data Analysis. It is very essential to deal with NaN in order to get the desired results. In this article, we will discuss how to drop rows with NaN values.
Pandas DataFrame dropna() Method
We can drop Rows having NaN Values in Pandas DataFrame by using dropna() function
df.dropna()
It is also possible to drop rows with NaN values with regard to particular columns using the following statement:
df.dropna(subset, inplace=True)
With in place set to True and subset set to a list of column names to drop all rows with NaN under those columns.
Example 1:
In this case, we’re making our own Dataframe and removing the rows with NaN values so that we can see clean data.
Python3
# importing librariesimport pandas as pdimport numpy as npnum = {'Integers': [10, 15, 30, 40, 55, np.nan, 75, np.nan, 90, 150, np.nan]}# Create the dataframedf = pd.DataFrame(num, columns=['Integers'])# dropping the rows having NaN valuesdf = df.dropna()# printing the resultdf |
Output:
Example 2:
In this example, we drop the rows having NaN values and then reset the indices using the method reset_index()
df = df.reset_index(drop=True)
Python3
# importing librariesimport pandas as pdimport numpy as npcar = {'Year of Launch': [1999, np.nan, 1986, 2020, np.nan, 1991, 2007, 2011, 2001, 2017], 'Engine Number': [np.nan, 15, 22, 43, 44, np.nan, 55, np.nan, 57, np.nan], 'Chasis Unique Id': [4023, np.nan, 3115, 4522, 3643, 3774, 2955, np.nan, 3587, np.nan]}# Create the dataframedf = pd.DataFrame(car, columns=['Year of Launch', 'Engine Number', 'Chasis Unique Id'])# dropping the rows having NaN valuesdf = df.dropna()# To reset the indicesdf = df.reset_index(drop=True)# Print the dataframedf |
Output:
Example 3:
In the example, we used thresh = 2 inside the df.dropna() function which means it will drop all those rows where Nan/NaT values are 2 or more than 2, others will remain as it is.
Python3
# Importing librariesimport pandas as pdimport numpy as np# Creating a dictionarydit = {'August': [10, np.nan, 34, 4.85, 71.2, 1.1], 'September': [np.nan, 54, 68, 9.25, pd.NaT, 0.9], 'October': [np.nan, 5.8, 8.52, np.nan, 1.6, 11], 'November': [pd.NaT, 5.8, 50, 8.9, 77, pd.NaT]}# Converting it to data framedf = pd.DataFrame(data=dit)# Dropping the rows having NaN/NaT values# when threshold of nan values is 2df = df.dropna(thresh=2)# Resetting the indices using df.reset_index()df = df.reset_index(drop=True)df |
Output:
Example 4:
In the example, we use subset = [‘October’] inside the df.dropna() function which means it will remove all rows having Nan/NaT values under the label ‘October’.
Python3
# Importing librariesimport pandas as pdimport numpy as np# Creating a dictionarydit = {'August': [10, np.nan, 34, 4.85, 71.2, 1.1], 'September': [np.nan, 54, 68, 9.25, pd.NaT, 0.9], 'October': [np.nan, 5.8, 8.52, np.nan, 1.6, 11], 'November': [pd.NaT, 5.8, 50, 8.9, 77, pd.NaT]}# Converting it to data framedf = pd.DataFrame(data=dit)# Dropping the rowns having NaN/NaT values# under certain labeldf = df.dropna(subset=['October'])# Resetting the indices using df.reset_index()df = df.reset_index(drop=True)df |
Output:
