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Pandas to_numeric function

As explained in Pandas Workout: 200 exercises to make you a stronger data analyst

to_numeric is a pandas function that converts values to numeric data, optionally coercing unconvertible values to missing values.

pd.to_numeric converts values into numeric data. With errors='coerce', it replaces unconvertible values with NaN instead of raising an exception. section 5.6

Clean an age column

Convert celebrity-death ages with df['age'] = pd.to_numeric(df['age'], errors='coerce'), inspect the result with describe(), then retain plausible ages using df.loc[df['age'] < 120]. This catches both nonnumeric entries and values such as 9394 that convert successfully but remain implausible. section 5.6

df['age'] = pd.to_numeric(df['age'], errors='coerce')

Use the concise coercion pattern for converting a pandas column while marking failed conversions as missing. section 5.6

A practical cleanup sequence is:

  • Convert the column with pd.to_numeric. section 5.6
  • Inspect descriptive statistics to find suspicious converted values. section 5.6
  • Filter the cleaned data using a domain-specific threshold. section 5.6

How Pandas Workout: 200 exercises to make you a stronger data analyst covers it

How deep it goes
Explains default exceptions, coercion to NaN, inferred numeric types, and post-conversion plausibility checks.
Examples
Uses a celebrity-death dataset, an age column, describe(), and a less-than-120 plausibility filter.
What it assumes
Assumes familiarity with pandas columns, assignment, missing values, and filtering.
What you can do after
Apply pandas conversion and diagnose implausible numeric results before calculating with cleaned data.
How it connects
Connects numeric conversion to missing values, descriptive statistics, boolean indexing, and data cleaning.

Related concepts

This explainer was generated by Manning's knowledge graph from the text of Pandas Workout: 200 exercises to make you a stronger data analyst. The section links point to the parts of the book it draws on.