You can set/change the value to a particular cell in a pandas DataFrame for a given Index by using DataFrame.at[] and DataFrame.loc[] methods. Setting a value to a cell modifies the DataFrame with a new value at some index. In this article, I will explain how to set values for a particular cell in DataFrame using an index with examples.
1. Quick Examples of Set Value for Particular Cell in DataFrame using index
If you are in a hurry, below are some quick examples of how to set/change the value for a particular cell in DataFrame using an index.
# Below are quick example
# Use DataFrame.at[] method to set value for particular cell
df.at[0,'Courses'] = 'Java'
df.at[1,'Fee'] = 40000
df.at[2,'Duration'] = '55days'
# Use Dataframe.loc[] method to set value for particular cell
df.loc[0, 'Duration'] = "45days"
df.loc[1, 'Courses'] ="Python"
df.loc[3, 'Fee'] = 45000
Now, let’s create a DataFrame with a few rows and columns, execute these examples and validate results. Our DataFrame contains column names Courses, Fee, Duration, and Discount.
import pandas as pd
technologies = [
("Spark", 22000,'40days',1500),
("PySpark",25000,'50days',3000),
("Hadoop",23000,'30days',2500),
("Pandas",30000,'60days',2800)
]
df = pd.DataFrame(technologies,columns = ['Courses','Fee','Duration','Discount'])
print(df)
Yields below output.
Courses Fee Duration Discount
0 Spark 22000 40days 1500
1 PySpark 25000 50days 3000
2 Hadoop 23000 30days 2500
3 Pandas 30000 60days 2800
2. Use DataFrame.at[] to Set Value for Particular Cell
pandas.DataFrame.at[] method is primarily used when you need to set a single value in pandas DataFrame. while accessing the cell you have to specify the index and column as DataFrame.at[0,'Courses']. This example changes the value of the Courses column of the first row. The first parameter is the index, and the second is the column.
# Use DataFrame.at[] method to set value for particular cell
df.at[0,'Courses'] = 'Java'
df.at[1,'Fee'] = 40000
df.at[2,'Duration'] = '55days'
df.at[3,'Discount'] = 4000
print(df)
Yields below output.
Courses Fee Duration Discount
0 Java 22000 40days 1500
1 PySpark 40000 50days 3000
2 Hadoop 23000 55days 2500
3 Pandas 30000 60days 4000
3. Use Dataframe.loc[] Method to Set Value for Particular Cell using index
You can also use DataFrame.loc[] method to set value for particular cell. For instance, DataFrame.loc[row_index,col_indexer]=value.
# Use Dataframe.loc[] method to set value for particular cell
df.loc[1, 'Courses'] ="Python"
df.loc[3, 'Fee'] = 45000
df.loc[0, 'Duration'] = "45days"
df.loc[2, 'Discount'] = 2500
print(df)
Yields below output.
Courses Fee Duration Discount
0 Spark 22000 45days 1500
1 Python 25000 50days 3000
2 Hadoop 23000 30days 2500
3 Pandas 45000 60days 2800
4. Complete Example For Set Value for Particular Cell in DataFrame using index
import pandas as pd
technologies = [
("Spark", 22000,'40days',1500),
("PySpark",25000,'50days',3000),
("Hadoop",23000,'30days',2500),
("Pandas",30000,'60days',2800)
]
df = pd.DataFrame(technologies,columns = ['Courses','Fee','Duration','Discount'])
print(df)
# Use DataFrame.at[] method to set value for particular cell
df.at[0,'Courses'] = 'Java'
df.at[1,'Fee'] = 40000
df.at[2,'Duration'] = '55days'
df.at[3,'Discount'] = 4000
# Use Dataframe.loc[] method to set value for particular cell
df.loc[1, 'Courses'] ="Python"
df.loc[3, 'Fee'] = 45000
df.loc[0, 'Duration'] = "45days"
df.loc[2, 'Discount'] = 2500
print(df)
Conclusion
In this article, you have learned how to set/change/update a value for particular cell in pandas DataFrame using index by using DataFrame.at[] and DataFrame.loc[] methods with examples
Happy Learning !!
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