# Excel-formulas-calculator

Excel-formulas-calculator (EFC) is a high-level Py23 library that allows you to calculate Excel formulas on any OS.

## Openpyxl interface

```
from openpyxl import load_workbook
from efc.interfaces.iopenpyxl import OpenpyxlInterface
wb = load_workbook('test.xlsx')
interface = OpenpyxlInterface(wb=wb, use_cache=True)
# e.g. A1 stores formula '=1 + 2', then result = 3
result = interface.calc_cell('A1', 'Worksheet1')
# EFC does not change the source document
print(wb['Worksheet1']['A1'].value) # prints '=1 + 2'
# If you need to replace a formula in a workbook with a value,
# you need to do this
wb['Worksheet1']['A1'].value = interface.calc_cell('A1', 'Worksheet1')
print(wb['Worksheet1']['A1'].value) # prints '3'
# The EFC does not track changes to values in the workbook.
# If the use_cache=True option is used, the calculated formulas
# are not recalculated again when they are accessed.
# e.g. A2 = 2, A3 = 1, A4 = A2 + A3
print(interface.calc_cell('A4', 'Worksheet1')) # prints '3'
wb['Worksheet1']['A2'].value = 1234
print(interface.calc_cell('A4', 'Worksheet1')) # prints '3'
# If you have made changes to the workbook, then you need to reset
# the cache to get up-to-date results
interface.clear_cache()
print(interface.calc_cell('A4', 'Worksheet1')) # prints '1235'
# You can disable caching of results,
# but then when you run a large number of related formulas,
# the calculation speed will decrease significantly
```

## Custom interface

- Inherit from efc.interface.BaseExcelInterface in your excel file class and implement abstract methods. This class will be used to get data from excel file using any library you want.
- Use calc_cell to calculate cell’s formula.

### Functionality

- Arithmetic:
`-, +, *, /, ^, ()`

- Comparison:
`<>, >, >=, <, <=, =`

- String concatenation:
`&`

- Functions:
`ABS, AND, AVERAGE, AVERAGEIFS, CONCATENATE, COUNT, COUNTA, COUNTIF, COUNTIFS, COUNTBLANK, FLOOR, IF, IFS, IFERROR, INDEX, ISBLANK, ISERROR, LARGE, LEN, LEFT, LOWER, MATCH, MAX, MID, MIN, MOD, NOT, OFFSET, OR, RIGHT, ROUND, ROUNDDOWN, SEARCH, SMALL, SUBSTITUTE, SUM, SUMIF, SUMIFS, TRIM, VLOOKUP, YEARFRAC, UPPER`

- All variations of the spelling of the cell and range addresses (linked docs will be skipped)
- Formula cell offset – this can be useful when calculating shared formulas