Pandas Replace Nan With 0

In this Python Pandas tutorial, will learn how to replace nan value with 0 in Python using Pandas. Also, we will cover these topics.

Pandas replace nan with 0 in column
Pandas replace nan with 0 for multiple columns
Pandas replace nan with 0 in one column
Pandas replace nan with 0 inplace
Pandas substitute nan with 0
Pandas series replace nan with 0
Pandas merge replace nan with 0
Pandas fill nan values with 0
Pandas read_csv replace nan with 0
Pandas replace nan with 0 in all columns
replace nan with 0 pandas list
Pandas replace string nan with 0
Pandas sum replace nan with 0
Pandas pivot replace nan with 0

Table of Contents

Pandas replace nan with 0

In this program, we will discuss how to replace nan values with zero by using Pandas DataFrame.
In Python, Programming nan stands for not a number. These are the special values in NumPy arrays as well as Pandas and it represents the missing of values in a Dataset.
In Python mostly we can replace Nan values with blank strings but in this article, we will discuss how to replace nan values with zeros in Pandas DataFrame.
There are various approaches to solve this problem. Let’s take an example and understand what exactly nan values work in Pandas and how to replace nan with zero.
- By using Fill.na() method
- By using replace() method

By using Fill.na() method

This method is used to fills in missing values in Pandas DataFrame. While in the case of the NumPy array it has the np.nan which indicates a missing numeric value.

Syntax:

Here is the Syntax of fill.na() method

DataFrame.fillna
               (
                value=None,
                method=None,
                axis=None,
                inplace=False,
                limit=None,
                downcast=None
               )

It consists of few parameters
- Value: This parameter specifies the value that will be used to fill the null values. In this article, you have to provide a single value that is 0 and this will be used to fill in all of the missing values in Pandas Dataframe.
- method: This parameter is used to fill the missing values in the Series and by default its value is None.
- axis: This method takes only integer or string values for columns and rows
- inplace: By default this parameter is set to inplace =False which means it does not fill values at an empty place.

Example:

Let’s take an example and check how to use fill.na() method in Pandas

import pandas as pd
import numpy as np

df = pd.DataFrame({'new_val': [np.nan, np.nan, np.nan, np.nan]})
df['new_val'] = df['new_val'].fillna(0)

print (df)

In the above program, we take a DataFrame with np. nan values. Now we will use the fillna() method to replace these values np. nan values with zeros.

Here is the execution of the following given code

By using replace() method

This is another approach to replace nan value with zeros by using Pandas DataFrame.
By using the Pandas.replace() method the values of the Pandas DataFrame can be replaced with other values like zeros.

Syntax:

Here is the Syntax of Pandas.replace() method

DataFrame.replace
                 (
                  to_replace=None,
                  value=None,
                  inplace=False,
                  limit=None,
                  regex=False,
                  method='pad'
                 )

Source Code:

import pandas as pd
import numpy as np

new_dictionary = {'Employee_name': ['George','Micheal','William','Liah','Oliva','Elite','James','Potter'],
		'Employee_id': [ np.nan, 763, np.nan, np.nan, 279,np.nan,99928,np.nan],

	'Employee_age': [277, np.nan, np.nan, np.nan, 267, 2883, np.nan, 829]}

df = pd.DataFrame(new_dictionary)
new_result = df.replace(np.nan, 0)
print(new_result)

You can refer to the below Screenshot

Read: How to Add a Column to a DataFrame in Python Pandas

Pandas replace nan with 0 in column

Let us see how to replace nan values with zeros in column in Python.
To perform this particular task we can apply the DataFrame.fillna() method. In this program, we will see how to replace nan values in columns.
In Python, this function is used to fill out the missing values in the given DataFrame and replace those values with zeros.

Example:

import pandas as pd
import numpy as np

df = pd.DataFrame(
	[[np.nan, np.nan, 745],
	[567, np.nan, 156],
	[348, 118, np.nan],
	[np.nan, np.nan, np.nan]],
	columns=['Australia', 'Germany', 'China'])

df['China'] = df['China'].fillna(0)
df['Germany'] = df['Germany'].fillna(0)
df['Australia'] = df['Australia'].fillna(0)
print("Updated DataFrame",df)

In the above code first, we have created a DataFrame ‘df’ and then assign a nan and numeric value in it. Now select a particular column element along with Fillna() method. Once you will print ‘df’ then the output will display only zero’s and numeric integer values.

Here is the Screenshot of the following given code

Read: How to Convert Pandas DataFrame to NumPy Array in Python

Pandas replace nan with 0 for multiple columns

Here we can see how to replace nan values with zeros for multiple columns by using replace() method in Python Pandas.
In Python, this method is used for data cleaning, and this technique is used for replacing nan values with zeros in multiple columns. When you are using this method in any DataFrame then it will replace every instance of the value in any column.

Let’s look at an example

Source Code:

import pandas as pd
import numpy as np
new_dict = {'Stu_name': ['William', 'Jmaes', 'Chris', 'Hemsowrth'],
            'Stu_age': [14, np.nan, np.nan, 34],
            'Stu_name': [998, np.nan, 157,np.nan],
             'Stu_marks':[167, np.nan,556,np.nan]}
df = pd.DataFrame(new_dict)


df['Stu_age'] = df['Stu_age'].replace(np.nan,0)
df['Stu_marks'] = df['Stu_marks'].replace(np.nan,0)

print("Updated DataFrame",df)

In the above code first, we just import the packages that we will need to execute this program. Now we have created a simple DataFrame object and this DataFrame contains ‘Student_information’.

The DataFrame has four variables ‘Columns’. Now we want to display only multiple columns in the new DataFrame. To do this we will use replace() method along with column name in the list.

Here is the implementation of the following given code.

Pandas replace nan with 0 for multiple columns

Read: How to Find Duplicates in Python DataFrame

Pandas replace nan with 0 in one column

In this Program, we will discuss how to replace nan values with zeros in a specific column of Pandas DataFrame.
To do this task we will use DataFrame.fillna() method and this function will help the user to replace a value in a specific column. In this example, we will mention the column name in the list and then use the fillna() method. Once you will print the ‘df’ then the output will display only one column value ‘Japan’.

Example:

import pandas as pd
import numpy as np

df = pd.DataFrame(
	[[np.nan, np.nan, 456],
	[110, np.nan, 145],
	[np.nan, 113, np.nan],
	[np.nan, np.nan, np.nan]],
	columns=['Japan', 'U.S.A', 'England'])

df['Japan'] = df['U.S.A'].fillna(0)
print("Updated DataFrame",df)

You can refer to the below Screenshot

As you can see in the Screenshot the new dataframe contains zeros values in the ‘Japan’ column name.

Read: Add row to Dataframe Python Pandas

Pandas replace nan with 0 inplace

Let us see how to replace nan values with 0 by using inplace parameter in it in Pandas.
In this method, the inplace parameter is set to inplace =True which means that it will fill in the null values and directly modify the original Pandas DataFrame. If you set inplace =True then it fills values at an empty place.
By default, this method takes inplace=’False’ value which means a new dataframe with resultant content is returned.

Source Code:

import pandas as pd
import numpy as np
Student_info = {'Stu_name': ['Hayden', 'Adam', 'Mathew', 'Gilchrist'],
        'Stu_age': [16, 18, np.nan, np.nan],
        'Stu_marks': [180, np.nan, 340,np.nan]}
df = pd.DataFrame(Student_info)
df.fillna(0, inplace=True)
print(df)

Here is the Screenshot of the following given code

Pandas replace nan with 0 inplace — Pandas replace nan with 0 in place

Read: Check If DataFrame is Empty in Python Pandas

Pandas substitute nan with 0

Here we can see how to substitute nan value with zero in Pandas DataFrame.
By using the Pandas.replace() method we can perform this particular task and change the numeric integer value with 0.

Source Code:

import pandas as pd
import numpy as np

new_dictionary = {'Employee_name': ['Brett','lee','John','Liah','Oliva','Elite','James','Potter'],
		'Employee_id': [ np.nan, 157, np.nan, np.nan, 239,np.nan,445,np.nan],

	'Employee_age': [277, np.nan, np.nan, np.nan, 267, 2883, np.nan, 829]}

df = pd.DataFrame(new_dictionary)
new_result = df.replace(np.nan, 0)
print(new_result)

In the above program, we take a DataFrame with np.nan values. Now we will use DataFrame.replace() method to replace these values np.nan values with zeros.

Here is the execution of the following given code

Read: Python Pandas replace multiple values

Pandas series replace nan with 0

In this Program, we will discuss how to replace nan value with 0 by using Pandas Series.
In Python Pandas series can only store a single list with an index and the dataframe is a collection of series to analyze the data. We can also convert the dictionary, list, and tuple into series by using the pandas “series” method.
Now in this program, we will check how to replace nan values with zeros by creating a DataFrame object.

Example:


import pandas as pd
import numpy as np

new_series = {'val1': [15, np.nan, 536, np.nan, 22, 234, np.nan,
						np.nan, 82, np.nan],
	'val2': [19, 25, np.nan, np.nan, 11, np.nan,
						np.nan, 234, 119, np.nan],
	'val3': [16, 856, np.nan, np.nan, np.nan, 3312, 9913,
						19, 1567, np.nan]}

df = pd.DataFrame(new_series)
df = df.fillna(0)
print(df)

In the above code first, we have imported pandas and NumPy library and then create a dictionary in which we have to assign numeric integer as well as nan values.

Here is the implementation of the following given code

Read: How to Set Column as Index in Python Pandas

Pandas merge replace nan with 0

Here we can see how to merge two different dataframe and replace nan value with zero by using the Pandas.Concat() method.
In Python, this function is used to combine dataframe series together along with an axis of Pandas object. In this method, we can also pass various arguments to modify the behavior of the Pandas concatenation operation.

Syntax:

Here is the Syntax of Pandas.Concat() method

Pandas.Concat
             (
              objs,
              axis=0,
              join='outer',
              ignore_index=False,
              keys=None,
              Levels=None,
              names=None,
              verify_integrity=False,
              sort=False,
              copy=True
             )

It consists of few Parameters
- objs: This parameter specifies the sequence of series or dataframe objects and if the mapping series is passed the sorted keys will be used as a key parameter.
- axis: By default, its value is 0 and it is used to concatenate along with the axis in the dataframe. If axis=1 then it performs column-wise.
- join: This parameter indicates how to control indexes on other axes.
- ignore_index: By default, its value is false if it is true then do not use index value on the given axis.
- keys: By default, its value is None and should contain only tuple values.
- Levels: This parameter specifies the levels (list of sequence) and by default, it takes none value.

Let’s take an example and check how to merge two dataframe series and also replace nan values with zeros

Source Code:

import pandas as pd
import numpy as np

new_series = pd.DataFrame({'Student_age': [np.nan, 67, np.nan, 88],
					'Student_marks': [45, np.nan, 456, np.nan]})

new_col = pd.DataFrame({'Student_age': [134, np.nan, 578, np.nan],
					'Student_marks': [764, np.nan, 1457, np.nan]})


new_val = [new_series, new_col]

result = pd.concat(new_val)
df = result.fillna(0)
print(df)

In the above program first, we have created two different dataframe ‘new_series’ and ‘new_col’ which contain integers and nan values.

Now declare a list and assign the column names to it. After that use Pandas.concat() method for concatenating two series with list parameters.

Here is the execution of the following given code

Read: Python DataFrame to CSV

Pandas fill nan values with 0

In this Program, we will discuss how to replace nan values with 0 by using the fillna() method in Python Pandas.
In Python Pandas this method is used to fill NA/NAN values and it always returns the Pandas DataFrame object with missing values. These are the special values in NumPy arrays as well as Pandas and it represents the missing of values in a Dataset.

Syntax:

Here is the Syntax of Pandas.fillna() method

DataFrame.fillna
               (
                value=None,
                method=None,
                axis=None,
                inplace=False,
                limit=None,
                downcast=None
               )

Source Code:

import pandas as pd
import numpy as np

df = pd.DataFrame(
	[[np.nan, np.nan, 456],
	[178, np.nan, 756],
	[np.nan, 129, np.nan],
	[np.nan, np.nan, np.nan]],
	columns=['Oliva', 'Elijah', 'Chris'])

df['Elijah'] = df['Elijah'].fillna(0)
print("Updated DataFrame",df)

In the above program, we take a DataFrame with np. nan values. Now we will use the fillna() method to replace these values np. nan values with zeros.

You can refer to the below Screenshot

Read: Get index Pandas Python

Pandas replace nan with 0 in all columns

Let us see how to replace nan value with zeros in all columns in Python Pandas.
To perform this particular task we can apply the method Pandas.fillna() method. In this example we will replace all nan values which are available in the given list.

Example:

import pandas as pd
import numpy as np

df = pd.DataFrame(
	[[np.nan, np.nan, 267],
	[117, np.nan, 881],
	[107, 578, np.nan],
	[np.nan, np.nan, np.nan]],
	columns=['Micheal', 'Liah', 'Oliva'])

df['Micheal'] = df['Micheal'].fillna(0)
df['Liah'] = df['Liah'].fillna(0)
df['Oliva'] = df['Oliva'].fillna(0)
print("Updated DataFrame",df)

In the above code first, we have created a DataFrame ‘df’ and then assign a nan and numeric value in it. Now select a particular column element along with fillna() method. Once you will print ‘df’ then the output will display only zero’s and numeric integer values.

Here is the execution of the following given code

Pandas replace nan with 0 in all columns

Read: Python Pandas Write DataFrame to Excel

Replace nan with 0 pandas list

Here we can see how to replace nan values with zeros in a list by using Pandas.
In this Program, we have imported a pandas library and then create a list that contains integer and nan values. Now iterate through a values use list comprehension method.
In Python, the list comprehension method is used to create a list by performing an operation on each item in the existing list.

Source Code:

import pandas as pd

new_lis = [78, pd.NA, 157, pd.NA,pd.NA,456,pd.NA]
new_lis = [0 if pd.isna(m) else m for m in new_lis]
print("upgraded dataframe",new_lis)

Here is the implementation of the following given code

Read: Count Rows in Pandas DataFrame

Pandas replace string nan with 0

In this program, we will see how to replace nan string values with zero in Pandas. To do this task we will use the replace() method.
By using the Pandas.replace() method the values of the Pandas DataFrame can be replaced with other values like zeros.

Example:

import pandas as pd
import numpy as np
new_dict = {'Stu_name': ['John', 'Potter', 'Ghilchrist', 'Adam','np.nan','np.nan'],
            'Country_name': ['Japan', 'China', 'Germany', 'Australia'],
            'Stu_name': ['np.nan', 'np.nan', 157,'np.nan'],
             'Stu_marks':[167, 'np.nan',556,'np.nan']}
df = pd.DataFrame(new_dict)


df['Stu_name'] = df['Stu_name'].replace('np.nan',0)
df['Stu_marks'] = df['Stu_marks'].replace('np.nan',0)

print("Updated DataFrame",df)

In the above code first, we have created a dictionary and assign a key-value pair element. In this example, the key is considered as a column name and the list contains only string values. Now we want to replace the ‘np.nan’ value with zeros by using replace() method.

You can refer to the below Screenshot

Read: Python Pandas DataFrame Iterrows

Pandas sum replace nan with 0

Let us see how to sum all the integer values in the given dataframe by using Pandas.sum() method in Python Pandas.
In Python the Pandas provide a function that is sum() and can be used to get the sum of all values in a Pandas dataframe along with axis and this method always return a series that stores the sum of all the values in each column.

Syntax:

Here is the Syntax of Pandas.sum() method

DataFrame.sum(
              axis=None,
              skipna=None,
              level=None,
              numeric_only=None,
              min_count=0
             )

It consists of few parameters
- axis: This parameter indicates the sum of values will be calculated. If axis=1 that means the sum of values represented by columns.
- skipna: By default it takes true value.
- level: By default none and integer or level name.

Source Code:

import numpy as np
import pandas as pd

my_new_dict = { 'val1': [723, 1178, np.NaN, np.NaN],
                'val2': [867, np.NaN, np.NaN, 289],
                'val3': [356, np.NaN, np.NaN, 190],
                'val4': [115, 590, 389, 178],
                'col_name': ['Python', 'Java', 'Ruby', 'Sql']}

df = pd.DataFrame(my_new_dict)
df = df.set_index('col_name')
new_val=df['val2'].sum()
print(new_val)

In the above program, we have called the sum() function on this Pandas DataFrame without any axis argument. So, it displays a Dataframe series where each value in the series represents the sum of values in a column.

You can refer to the below Screenshot

Read: Python convert DataFrame to list

Pandas pivot replace nan with 0

In this Python program, we will discuss how to replace nan value with zero by using pivot and replace function.
In Python this function represents pivot table based on uniques values and also fills with values.

Syntax:

Here is the Syntax of Pandas.pivot() function

DataFrame.pivot(
                index=None,
                columns=None,
                values=None
               )

Example:

import pandas as pd
import numpy as np
new_dict = {'Stu_name': ['William', 'Jmaes', 'Chris', 'Hemsowrth'],
            'Stu_age': [14, np.nan, np.nan, 34],
            'Stu_name': [998, np.nan, 157,np.nan],
             'Stu_marks':[167, np.nan,556,np.nan]}
df = pd.DataFrame(new_dict)


df['Stu_age'] = df['Stu_age'].replace(np.nan,0)
df['Stu_marks'] = df['Stu_marks'].replace(np.nan,0)

print("Updated DataFrame",df)

Here is the Output of the following given code

Read How to aggregate numeric values using crosstab() in Pandas Python

In this Python Pandas tutorial, we have learned how to replace nan value with 0 in Python using Pandas. Also, we have covered these topics.

Pandas replace nan with 0 in column
Pandas replace nan with 0 for multiple columns
Pandas replace nan with 0 in one column
Pandas replace nan with 0 inplace
Pandas substitute nan with 0
Pandas series replace nan with 0
Pandas merge replace nan with 0
Pandas fill nan values with 0
Pandas read_csv replace nan with 0
Pandas replace nan with 0 in all columns
replace nan with 0 pandas list
Pandas replace string nan with 0
Pandas sum replace nan with 0
Pandas pivot replace nan with 0

Bijay Kumar

I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etc… for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.

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