Simple spreadsheet extension for reStructuredText tables.

## Project description

Register a simplespreadsheet directive to do calculations in a table.

## Install

```pip install rst_simplespreadsheet  # or
```

## Usage

Use it as an extension to rst2pdf:

```rst2pdf -e rst_simplespreadsheet ...
```

## Syntax

Formulae are pieces of text enclosed in ={…}. Only one formula per cell is supported.

The simplest formula is a number, like this:

```={4}
```

This define the cell value to 4. A cell has value 0 (zero) unless it contains a formula.

You can reference the value of other cells using alphanumerical identifiers. Columns are identified using letters, from a to z then from aa to az, ba to bz and so on. Rows are identified using numbers. The first row is 1 and header rows are not numbered (thus not referenceable).

For example, the formula to calculate the product of cells a1 and a2 is:

```={a1 * a2}
```

There are two special characters, # and @, used to reference the current row and the current column, respectively.

For example, to calculate the product of cells b and f on the current row:

```={b# * f#}
```

and to calculate the sum of rows 1 and 2 in the current column:

```={@1 + @2}
```

### Functions

The spreadsheet can calculate cell values using Python functions. These functions have to be defined and registered in the SpreadSheet class first.

For now, only the function sum is defined:

```={sum("a1:a20")}
```

## Examples

You can do a simple table with totals like this one:

Qty Rate Price
2 1 \$ 2 \$
4 3 \$ 12 \$
1 5 \$ 5 \$
3 7 \$ 21 \$
Total 40 \$

with this code:

```.. simplespreadsheet::
+------+--------+-------------------+
| Qty  | Price  |  Total            |
+======+========+===================+
| ={2} | ={1} \$ | ={a# * b#} \$      |
+------+--------+-------------------+
| ={4} | ={3} \$ | ={a# * b#} \$      |
+------+--------+-------------------+
| ={1} | ={5} \$ | ={a# * b#} \$      |
+------+--------+-------------------+
| ={3} | ={7} \$ | ={a# * b#} \$      |
+------+--------+-------------------+
| *Total*       | ={sum("c1:c4")} \$ |
+------+--------+-------------------+
```

## Project details

This version 0.1.1 0.1.0