Coding: Median Imputation in Python | Dataford Interview Questions

Write Python code to read a CSV and impute null values with median

Asked in the Technical Round stage. Coding portion.

Implement impute_csv(csv_text). The input is a CSV string with a header row. A null is an empty cell or the case-insensitive value null. For each column containing only numeric non-null values, replace nulls with that column's median. Leave nonnumeric columns, all-null columns, and existing values unchanged. Return the resulting CSV string with the same header and row order. For an even number of values, use the arithmetic mean of the two middle values. Median replacements should be represented as decimal text.

Constraints

The input is a valid CSV string with one header row.
Every data row has the same number of columns as the header.
A null is an empty cell or a case-insensitive null value.
Numeric columns contain decimal or integer values when non-null.
Return the header and rows in their original order.

Function Signature

def impute_csv(csv_text):

Your question is Coding: Median Imputation in Python. Start with the requirements in the Question tab.

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Problem

Write Python code to read a CSV and impute null values with median

Asked in the Technical Round stage. Coding portion.

Constraints

The input is a valid CSV string with one header row.
Every data row has the same number of columns as the header.
A null is an empty cell or a case-insensitive null value.
Numeric columns contain decimal or integer values when non-null.
Return the header and rows in their original order.

Function Signature

def impute_csv(csv_text):

Your question is Coding: Median Imputation in Python. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.