Pandas Column Type to String

May 29, 2022 | by Arround The Web | No comments

By the end of this tutorial, you will understand how to use the astype() function in Pandas. This function allows you to cast an object to a specific data type.

Let us go exploring.

Function Syntax

The function syntax is as illustrated below:

DataFrame.astype(dtype, copy=True, errors='raise')

The function parameters are as shown:

dtype – specifies the target data type to which the Pandas object is cast. You can also provide a dictionary with the data type of each target column.
copy – specifies if the operation is performed in-place, i.e., affects the original DataFrame or creating a copy.
errors – sets the errors to either ‘raise’ or ‘ignore.’

Return Value

The function returns a DataFrame with the specified object converted to the target data type.

Example

Take a look at the example code shown below:

# import pandas
import pandas as pd
df = pd.DataFrame({
'col1': [10,20,30,40,50],
'col2': [60,70,80,90,100],
'col3': [110,120,130,140,150]},
index=[1,2,3,4,5]
)
df

Convert Int to Float

To convert the ‘col1’ to floating-point values, we can do:

df.col1.astype('float64', copy=True)

The code above should convert ‘col1’ to floats as shown in the output below:

Convert to Multiple Types

We can also convert multiple columns to different data types. For example, we convert ‘col1’ to float64 and ‘col2’ to string in the code below.

print(f"before: {df.dtypes}\n")
df = df.astype({
'col1': 'float64',
'col2': 'string'
})
print(f"after: {df.dtypes}")

In the code above, we pass the column and the target data type as a dictionary.

The resulting types are as shown:

Convert DataFrame to String

To convert the entire DataFrame to string type, we can do the following:

df.applymap(str)

The above should cast the entire DataFrame into string types.

Conclusion

In this article, we covered how to convert a Pandas column from one data type to another. We also covered how to convert an entire DataFrame into string type.

Happy coding!!

Source: linuxhint.com