parqview

Keyboard-first terminal UI for exploring Parquet and CSV files with DuckDB-backed preview and profiling.

Why This Exists

parqview is for fast inspection of data as it moves through a pipeline.

Use it to quickly catch:

• pipeline failures that produce unexpected null-heavy outputs,
• join failures (duplicate columns, mismatched keys, broken join coverage),
• NaN/missing value spikes in critical features,
• out-of-distribution feature values before they break downstream models or checks.

The goal is smooth, low-friction, interactive data browsing with familiar and intuitive keyboard navigation.

Screenshot

Installation

Homebrew (recommended)

brew install robince/tap/parqview

Direct download from GitHub Releases

Download the archive for your platform from https://github.com/robince/parqview/releases.

macOS arm64 example:

VERSION="1.0.0"
curl -fL -o parqview.tar.gz "https://github.com/robince/parqview/releases/download/v${VERSION}/parqview_${VERSION}_darwin_arm64.tar.gz"
tar -xzf parqview.tar.gz
./parqview --version

Linux amd64 example:

VERSION="1.0.0"
curl -fL -o parqview.tar.gz "https://github.com/robince/parqview/releases/download/v${VERSION}/parqview_${VERSION}_linux_amd64.tar.gz"
tar -xzf parqview.tar.gz
./parqview --version

Note for direct macOS downloads: if Gatekeeper blocks first run, remove quarantine:

xattr -dr com.apple.quarantine ./parqview

Run

Open a file directly:

./parqview <file.parquet|file.csv>

Or run from source:

go run ./cmd/parqview <file.parquet|file.csv>

If the app starts without a file, press Ctrl+O to open the file picker.

Screens and Keys

Shortcuts below describe app-specific behavior. When a search input is focused, normal text editing keys are handled by the Charmbracelet Bubbles textinput component.

Main Workspace (Table + Columns)

This is the default screen with a data table on the left and columns list on the right.

Key	Action
Tab	Switch focus between table and columns panes
Ctrl+O	Open/close file picker (.parquet/.csv)
q, Ctrl+C	Quit
Ctrl+L	Redraw screen
?	Open/close help overlay
s, S	Toggle selected-columns view in data table
v, V	Toggle selected-columns view in columns pane (columns focus)
Enter	Open detail panel for active column
Space	Page down in focused pane

Columns Pane

Use this pane to search, triage, and build a selection set of columns.

Key	Action
/	Focus column search input
Up, k	Move cursor up 1 row
Down, j	Move cursor down 1 row
Space, Ctrl+F	Page down
Ctrl+B	Page up
Ctrl+D	Half-page down
Ctrl+U	Half-page up
g, Home	Jump to top of full list
G, End	Jump to bottom of full list
H	Jump to top of current visible list window
M	Jump to middle of current visible list window
L	Jump to bottom of current visible list window
x	Toggle selection on active (crosshair) column
a	Add all filtered columns to selection
d	Remove all filtered columns from selection
A	Select all columns
X	Clear all selected columns
y	Copy selected columns as a Python list
Enter	Open detail panel for active column

Table Pane

Use this pane to inspect row values, navigate missingness, and check distribution shifts.

Key	Action
Up, k	Move row cursor up
Down, j	Move row cursor down
Left, h	Move selected column left
Right, l	Move selected column right
0	Jump to first visible table column
$	Jump to last visible table column
[	Page table columns left
]	Page table columns right
w	Toggle fit-width for active column
Ctrl+W	Toggle global wide-columns mode
g	Jump to top row
G	Jump to bottom row
Space, Ctrl+F	Page down
Ctrl+B	Page up
Ctrl+D	Half-page down
Ctrl+U	Half-page up
r	Jump to next missing value in current row
R	Jump to previous missing value in current row
c	Jump to next row with missing value in selected column
C	Jump to previous row with missing value in selected column
f	Toggle missing-row filter
Enter	Open detail panel for selected column

Column Search Input (in Columns Pane)

Key	Action
Esc	Clear query and exit search
Enter	Commit query and exit search
Ctrl+U	Clear search query
Text editing keys	Edit search query

Detail Panel Overlay

Key	Action
t	Cycle tabs (Top Values, Stats, Histogram)
n	Jump to first missing value for detail column
Esc, q	Close detail panel

File Picker Overlay

Key	Action
Enter	Open selected file/folder
Backspace	Go to parent folder (when query is empty)
Ctrl+U	Clear picker query
Esc	Close file picker

Help Overlay

Key	Action
Esc, ?, q	Close help

Mouse

Action	Behavior
Mouse wheel	Scroll cursor in focused pane
Left-drag divider	Resize table/columns split

Technical Details: Missing Definition

By default, parqview treats both NULL and NaN as missing values for:

• missing indicators (orange dots/marker styles),
• missing-row filter (f),
• missing navigation (n, r/R, c/C),
• missing counts in profiling and footers.

This behavior is controlled by internal/missing/policy.go:

• IncludeNaNAsMissing = true (default): NULL + NaN
• IncludeNaNAsMissing = false: NULL only