Pandas
keyboard_arrow_down 655 guides
chevron_leftHandling Missing Values
Adding missing dates in Datetime IndexChecking if a certain value in a DataFrame is NaNChecking if a DataFrame contains any missing valuesConverting a column with missing values to integer typeCounting non-missing valuesCounting number of rows with missing valuesCounting the number of NaN in each row of a DataFrameCounting number of NaN values in each column of a DataFrameCounting the total number of NaN values of a DataFrameFilling missing values using another columnFilling missing values with the mean of the columnFinding columns with missing valuesGetting integer indexes of rows with NaNGetting rows with missing valuesGetting rows with missing values in certain columnsGetting index of rows with missing values (NaNs)Getting index of rows without missing valuesMapping NaN values to 0 and non-NaN values to 1Mapping NaN values to False and non-NaN values to TrueRemoving columns where some rows contain missing valuesRemoving rows from a DataFrame with missing valuesReplacing all NaN values of a DataFrameReplacing all NaN values with zeros in a DataFrameReplacing missing valuesReplacing missing values with constantsReplacing NaN with blank stringReplacing NaNs for certain columnsReplacing NaNs with preceding valuesReplacing values with NaNsUsing interpolation to fill missing values
check_circle
Mark as learned thumb_up
0
thumb_down
0
chat_bubble_outline
0
Comment auto_stories Bi-column layout
settings
Counting the total number of missing values (NaNs) of a Pandas DataFrame
schedule Aug 12, 2023
Last updated local_offer
Tags Python●Pandas
tocTable of Contents
expand_more Master the mathematics behind data science with 100+ top-tier guides
Start your free 7-days trial now!
Start your free 7-days trial now!
Example
Consider the following DataFrame with some NaN values:
df
A B Ca NaN 4.0 NaNb 3.0 NaN 7.0c NaN 5.0 8.0
Solution
To count the total number of NaN values in df:
Explanation
Here, the df.isna() returns a DataFrame of booleans where True indicates entries that are NaN:
A B Ca True False Trueb False True Falsec True False False
Internally, True is represented by 1 while a False is represented by 0. Therefore, summing up all the values of df would then tell us how many NaN values there are.
The problem with the DataFrame's sum() method is that we can only compute the sum of each row or column of df. What we want to do instead is to compute the sum of all the values of the DataFrame.
We can do this by extracting the values of df as a NumPy array via the values property, and then calling its sum() method:
Published by Isshin Inada
Edited by 0 others
Did you find this page useful?
thumb_up
thumb_down
Comment
Citation
Ask a question or leave a feedback...
thumb_up
0
thumb_down
0
chat_bubble_outline
0
settings
Enjoy our search
Hit / to insta-search docs and recipes!
