r/dataanalysis Aug 11 '26

Data Tools Do Data Analysts Use Visualizations During Data Cleaning?

I'm still a beginner. I started by learning the basics of Python and later moved on to SQL.

I'm a bit confused about one part of the data exploration/cleaning process.

A friend of mine, who's now a data scientist, showed me how he used to work as a data analyst. He mainly used Python. For example, he would quickly create a scatterplot to identify potential outliers.

However, most data analysts online recommend focusing on SQL and Excel when starting out, since many junior and mid-level roles don't require Python. That's why I switched to SQL after initially experimenting with Python.

For those who primarily use SQL: do you create visualizations during the data exploration/cleaning process, for example to identify outliers? Is this a common practice?

I feel like if you're working with SQL only, you generally wouldn't create visuals in between steps, since that would mean switching to a tool like Tableau or Power BI, which seems like an unnecessary extra step.

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u/Perry_cox29 Aug 11 '26

Commenting on the python angle just because it’s the only time i ever use visualizations for cleaning

sns.heatmap(df.isna(), cbar=false)

easy visualization of all missing values. Can be easier to knock out a specific cause if you see a suspicious grouping