moderndid.core.panel.panel_to_wide#

moderndid.core.panel.panel_to_wide(data: Any, idname: str, tname: str, separator: str = '_') → Any[source]#

Pivot a long panel to wide format.

Reshapes the data so that each unit occupies a single row. Time-varying columns are spread into one column per period while time-invariant columns are kept as-is.

Parameters:

dataDataFrame: Panel data in long format. Accepts any object implementing the Arrow PyCapsule Interface (__arrow_c_stream__), including polars, pandas, pyarrow Table, and cudf DataFrames.
idnamestr: Unit identifier column.
tnamestr: Time period column.
separatorstr: String inserted between the variable name and time label in the wide column names. Default "_".

Returns:

DataFrame: Wide-format DataFrame with one row per unit, in the same format as data.

See also

wide_to_panel: Inverse operation (wide to long).

Examples

In [1]: from moderndid import make_balanced_panel, panel_to_wide, load_favara_imbs
   ...: 
   ...: df = load_favara_imbs()
   ...: df = make_balanced_panel(df, idname="county", tname="year")
   ...: wide = panel_to_wide(df, idname="county", tname="year")
   ...: wide.head(5)
   ...: 
Out[1]: 
shape: (5, 39)
┌────────┬─────────┬──────────┬────────────┬───┬────────────┬────────────┬────────────┬────────────┐
│ county ┆ state_n ┆ w1       ┆ Dl_vloans_ ┆ … ┆ Dl_hpi_200 ┆ Dl_hpi_200 ┆ Dl_hpi_200 ┆ Dl_hpi_200 │
│ ---    ┆ ---     ┆ ---      ┆ b_1994     ┆   ┆ 2          ┆ 3          ┆ 4          ┆ 5          │
│ i64    ┆ i64     ┆ f64      ┆ ---        ┆   ┆ ---        ┆ ---        ┆ ---        ┆ ---        │
│        ┆         ┆          ┆ f64        ┆   ┆ f64        ┆ f64        ┆ f64        ┆ f64        │
╞════════╪═════════╪══════════╪════════════╪═══╪════════════╪════════════╪════════════╪════════════╡
│ 1001   ┆ 1       ┆ 0.975312 ┆ 0.270248   ┆ … ┆ 0.060576   ┆ 0.024043   ┆ 0.02454    ┆ 0.128786   │
│ 1007   ┆ 1       ┆ 0.975312 ┆ -0.101783  ┆ … ┆ 0.026326   ┆ -0.001457  ┆ 0.063339   ┆ 0.075017   │
│ 1009   ┆ 1       ┆ 0.975312 ┆ 0.464161   ┆ … ┆ 0.029511   ┆ 0.000463   ┆ 0.061479   ┆ 0.075183   │
│ 1015   ┆ 1       ┆ 0.975312 ┆ 0.280577   ┆ … ┆ 0.056214   ┆ 0.052125   ┆ 0.019661   ┆ 0.017381   │
│ 1021   ┆ 1       ┆ 0.975312 ┆ -0.398833  ┆ … ┆ 0.02722    ┆ -0.002381  ┆ 0.060601   ┆ 0.073253   │
└────────┴─────────┴──────────┴────────────┴───┴────────────┴────────────┴────────────┴────────────┘