Adventures in Machine Learning

Mastering Data Manipulation with Pandas to_numeric() Function

Pandas is a widely-used data manipulation tool in the Python programming language. One of its key functions is to_numeric(), which in essence converts data types into numeric data types.

This article will discuss the purpose, syntax, implementation, and use cases of Pandas to_numeric() to help you better understand how it can be utilized in your own programming projects.

Understanding Pandas to_numeric() Function

The Pandas to_numeric() function has the primary purpose of converting data types into numeric data types such as int64 or float64. This is useful when dealing with data that initially comes in non-numeric types such as strings or object types.

It is important to note that the data conversion happens in a vectorized manner, which basically means that the entire dataset is converted at once. This can save a lot of time compared to converting each value individually.

Syntax of Pandas to_numeric()

To use the to_numeric() function, one has to import the Pandas package. The syntax for the to_numeric() function involves passing an argument (such as a series or an array) into the function, with an optional errors argument.

The errors argument can take on different values such as ‘raise’, ‘coerce’, or ‘ignore’ and it determines what happens when non-numeric data is encountered during the conversion process. There is also an optional downcast argument that allows the user to downcast the converted data types into the smallest possible dtype, which can lead to memory savings.

Implementation of Pandas to_numeric()

Pandas to_numeric() function is simple to implement once you have the Pandas package installed in your system. Additionally, it is important to take into consideration the data type that you want to convert, as well as the value of the errors and downcast arguments.

For example, if you want to convert a Series called ‘numbers’ into integers, you can write the following code:


import pandas as pd

numbers = pd.Series([“1″,”2″,”3”])

numbers = pd.to_numeric(numbers, errors = ‘coerce’, downcast = ‘integer’)


This code will convert the numbers Series into integers, while handling any non-numeric values with an error of ‘coerce’ and downcasting the data type to the smallest possible integer dtype.

Use Cases of Pandas to_numeric()

One common use case of Pandas to_numeric() is downcasting data types. In certain cases, you may find that your data has more bits than are necessary to represent the data.

By downcasting, you can reduce the memory footprint of your data, and optimize your code’s performance. The smallest possible dtype is the int8 or the float16.

However, downcasting may involve a trade-off between speed and accuracy, especially if your data involves massive numbers. Another use case of Pandas to_numeric() is dealing with accuracy loss due to intrinsic constraints.

In some situations, when you are working with n-dimensional arrays, you may find that some of your numbers are too large to be represented accurately by floats. In such cases, to avoid the loss of accuracy, you can use Pandas to_numeric() function to convert the data type to a higher precision format.


The article has discussed the purpose, syntax, implementation, and use cases of Pandas to_numeric() function. It is important as a programmer to be aware of the different scenarios where this function can be applied.

Whether you are dealing with Massive numbers or trying to downcast data types, Pandas to_numeric() can help optimize your code’s performance and lead to better results. With this knowledge in hand, you can begin to use this function to your advantage in your programming projects.

Examples of Implementing Pandas to_numeric()

In this section, we will examine three examples of how to implement the Pandas to_numeric() function to help you better understand how it can be used in practice. Example 1: Passing series as the only parameter

In this example, we will pass a series of numeric strings to the to_numeric() function and convert them into integers.

Here’s how to do it:


import pandas as pd

numbers = pd.Series([“1″,”2″,”3″,”4″,”5”])

numbers = pd.to_numeric(numbers)





0 1

1 2

2 3

3 4

4 5

dtype: int64


As you can see, the to_numeric() function has successfully converted the series to integer data types. Example 2: Passing downcast parameter

In this example, we will convert a series into different data types and see the effect of the downcast parameter.

Here’s how to do it:


import pandas as pd

numbers = pd.Series([32500, 127, -278])

downcast_signed = pd.to_numeric(numbers, downcast=’signed’)

downcast_unsigned = pd.to_numeric(numbers, downcast=’unsigned’)

downcast_float = pd.to_numeric(numbers, downcast=’float’)

print(“Downcast to the smallest signed integer dtype”)


print(“Downcast to the smallest unsigned integer dtype”)



Downcast to float dtype”)





Downcast to the smallest signed integer dtype

0 32500

1 127

2 -278

dtype: int16

Downcast to the smallest unsigned integer dtype

0 32500

1 127

2 522

dtype: uint16

Downcast to float dtype

0 32500.0

1 127.0

2 -278.0

dtype: float32


As you can see, when we pass the downcast parameter, it reduces the size of the data type. In this example, we have downcasted the data types to the smallest signed integer dtype, the smallest unsigned integer dtype, and the float dtype.

Note that in the case of downcasting of nullable integer and float data type we may get warning messages. This can be silenced by the Pandas.options.

Example 3: Passing the error parameter

In this example, we will pass data to to_numeric() that contains non-numeric values, and see how the error parameter can be used. Here’s how to do it:


import pandas as pd

data = pd.Series([‘1’, ‘2’, ‘3’, ‘4’, ‘foo’, ‘5’])

numeric_data = pd.to_numeric(data, errors=’coerce’)





0 1.0

1 2.0

2 3.0

3 4.0

4 NaN

5 5.0

dtype: float64


As you can see, we’ve passed a Series that contains a non-numeric value (foo) and set the errors parameter to ‘coerce’, so Pandas will replace non-numeric values with NaN values.

Summary of Pandas to_numeric()

The Pandas to_numeric() function offers a range of benefits, including the ability to efficiently analyze data, easy conversion of non-numeric data types, and an open-sourced library that offers flexibility and customization options.

In addition to to_numeric(), Pandas offers many other functional capabilities to help you manipulate and analyze your data efficiently.

Whether you’re a beginner or an experienced programmer, with the numerous tutorials available that cover Python language fundamentals, Pandas functionality, and more, you can use these powerful tools to achieve your programming goals. In conclusion, the article has explored the purpose, syntax, and implementation of Pandas to_numeric() function, which is used in converting non-numeric data types to numeric data types.

We have also explored three practical examples to help you understand how the function can be used in practice. With this knowledge in hand, you can use to_numeric() to optimize your code’s performance, to save memory, and to ensure accurate data representation in cases of massive numbers.

The Pandas library offers a powerful suite of tools that makes data manipulation and analysis efficient and straightforward. As a reader, you’ve learned that Pandas to_numeric() function can help you streamline your data manipulation process and attain better results quickly.

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