# Pandas Pivot Computes a pivot table from a pandas DataFrame. ## Note on a pivot table A pivot table is easier to understand if we start off from the table itself: In the below DataFrame: ``` Column labels X Y Z Index A 1 2 3 B 4 5 6 C 7 8 9 ``` We have index `["A", "B", "C"]` and column labels `["X", "Y", "Z"]`. Values in this DataFrame can be accessed by specifying the index and the column label. For example: ```python df.loc["A", "X"] # 1 df.loc["A", "Y"] # 2 ``` Now, let's restructure the table by converting column labels into row values: ``` A X 1 A Y 2 A Z 3 B X 4 B Y 5 B Z 6 C X 7 C Y 8 C Z 9 ``` Let's add a column label to each of these columns: ``` R C V -------- A X 1 A Y 2 A Z 3 B X 4 B Y 5 B Z 6 C X 7 C Y 8 C Z 9 ``` Now, the first two columns uniquely identify the value in the third column. **Pivoting** is the reverse of this operation. - You start with the table above and produce the original one. - In pandas, this means telling it to use: - R column: `A`, `B`, `C` as the index (row labels). - C column: `X`, `Y`, `Z` as the column labels. - V column: The numbers (`1, 2, 3, ...`) as the values for each cell indexed by `[A, B, or C]` and `[X, Y, or Z]`. This can be done using: ```python df.pivot(index="R", columns="C", values="V") ``` The result: ``` X Y Z A 1 2 3 B 4 5 6 C 7 8 9 ``` Now the data is back to its original, structured form.  ## Input | Name | Data type | |---|---| | dataframe | DataFrame | | index | String | | columns | String | | values | String | ## Output | Data type | |---| | DataFrame |