# Python Extensions

&app; historically has always been a traditional application in the sense that you open it, use it to manipulate your financial data via the windows it presents, save your data and close the windows again. This has the inherent limitation that you can only do whatever the windows, menus and toolbars allow you to do.

Sometimes you might need a little more flexibility. For example, you need a report with just a little different information than what the built-in reports provide, or you want to automate a frequently recurring action. Such custom manipulations are ideal candidates to write in one or the other scripting language.

Starting with &app; version 2.4 you can write Python scripts to manipulate your financial data.

The Python extensions are an optional feature in the source code. To be able to use Python scripts, &app; must have been compiled with this option enabled, otherwise all what follows won’t work. At present this option is not enabled by default, so if you need this, you may have to compile &app; from source yourself.

The Python extensions come with a couple of ready to use scripts. This chapter will show you how to use some of these.

This chapter is not about how to write your own Python scripts. Refer to the developer documentation for that instead.

## Import Bills or Invoices

In order for the importer to work the data must be in a fixed field length, comma separated line format. A example Python script to convert a downloaded order is shown below.

    import sys
    import csv

    VENDOR_ID="000013"
    INFILE=sys.argv[1]
    INV_ID=sys.argv[2]
    try:
      ACCOUNT=sys.argv[3]
    except:
      ACCOUNT="Expenses:Materials General"

    Reader = csv.reader(open(INFILE), delimiter=',')

    # Need to ignore 1st and last rows

    for row in Reader:
      if row[0].isdigit(): # We only use numbered lines
        outline=(INV_ID + ",," + VENDOR_ID + ",,,," + row[1] + " > " + row[4] + ",ea," +
          ACCOUNT + "," + row[2] + "," + row[5].replace("GBP", "") + ",,,,no,,,,,,,,")
      print outline

Example of a downloaded vendor order from Rapid Electronics (UK).

    line number,product code,quantity,availability,product description,unit price,discounts,line total,delivery,sub total,vat,grand total
    1,47-3524,100,100 Available,BC848C SOT-23 NPN TRANSISTOR (INF) (RC),GBP0.03,GBP0.00,GBP0.03
    2,47-3278,30,30 Available,L78L05ACZ 0.1A +5V VOLTAGE REG (ST) (RC),GBP0.18,GBP0.00,GBP0.18
    3,22-0120,1,1 Available,Tube 34 14pin DIL socket, narrow7.62mm, without central support,GBP1.05,GBP0.00,GBP1.05
    4,22-0127,1,0 Available<br />1 on Back Order,Tube 17 28pin DIL socket, wide15.24mm, without central support,GBP1.22,GBP0.00,GBP1.22
    5,62-0368,1,1 Available,820R CR25 0.25W CF Resistor Pk 100,GBP0.50,GBP0.00,GBP0.50
    6,47-3130,100,100 Available,1N4001 1A 50V SILICON RECTIFIER DIODE RC,GBP0.01,GBP0.00,GBP0.01
    7,17-0310,1,1 Available,PROFESSIONAL MINATURE PROBE HOOK RED RC,GBP0.90,GBP0.00,GBP0.90
    8,17-0312,1,1 Available,PROFESSIONAL MINATURE PROBE HOOK BLACKRC,GBP0.90,GBP0.00,GBP0.90
    9,34-0655,1,1 Available,PROTOBLOC 2 BREADBOARD,GBP4.39,GBP0.00,GBP4.39
    10,18-0200,1,1 Available,PP3 9V ALKALINE BATTERY "Not For Retail Sale",GBP1.37,GBP0.00,GBP1.37
    ,,,,,,,,GBP4.95,GBP24.93,GBP4.35,GBP29.28

A similar file after processing with the Python script.

    MEC-0071,,000013,,,,34-0655 > PROTOBLOC 2 BREADBOARD,ea,Expenses:Materials General,1,4.39,,,,no,,,,,,,,
    MEC-0071,,000013,,,,18-0105 > PP3 / PP6 BATTERY CLIP 150MM (RC),ea,Expenses:Materials General,10,0.06,,,,no,,,,,,,,
    MEC-0071,,000013,,,,62-0370 > 1k CR25 0.25W CF Resistor Pk 100,ea,Expenses:Materials General,1,0.50,,,,no,,,,,,,,
    MEC-0071,,000013,,,,62-0354 > 220R CR25 0.25W CF Resistor Pk 100,ea,Expenses:Materials General,1,0.50,,,,no,,,,,,,,
    MEC-0071,,000013,,,,34-5548 > PLAIN DOCUMENT WALLET ASSORTED PK 50 RE,ea,Expenses:Materials General,1,6.95,,,,no,,,,,,,,
    MEC-0071,,000013,,,,62-0386 > 4k7 CR25 0.25W CF Resistor Pk 100,ea,Expenses:Materials General,1,0.50,,,,no,,,,,,,,
    MEC-0071,,000013,,,,34-0860 > COPPER CLAD SRBP SS 100 X 160 (RC),ea,Expenses:Materials General,5,0.50,,,,no,,,,,,,,
    MEC-0071,,000013,,,,18-0163 > PP3 BATTERY HOLDER WITH FLYING LEADS RC,ea,Expenses:Materials General,5,0.23,,,,no,,,,,,,,
    MEC-0071,,000013,,,,73-4290 > ATMEGA8-16PU 8-BIT MICRO 8K DIL-28 (RC),ea,Expenses:Materials General,3,1.99,,,,no,,,,,,,,
    MEC-0071,,000013,,,,81-0014 > BC108 NPN GP TRANSISTOR RC,ea,Expenses:Materials General,20,0.16,,,,no,,,,,,,,
    MEC-0071,,000013,,,,DELIVERY,ea,Expenses:Postage,1,4.95,,,,no,,,,,,,,
    MEC-0071,,000013,,,,VAT,tax,Expenses:VAT,1,4.35,,,,no,,,,,,,,

As can be seen there are some fields that are absent and some that are not required for import. The first line is not required and the last line is superfluous as &app; will total the order for us. All that is required is to take what we want and produce an output file with the correct format to import into &app;. In this case we join the part number and description fields and these become description in &app; invoice/bill. We need the qty and part price fields. Contrary to the header line VAT is not included by line and is always zero, the VAT is calculated on the last line as VAT on the order total.

This will cause problems later.

In this example I have assigned the Expenses:Materials General account to be the target account. This can be changed after import in the usual way, along with any other data. If there is no such account as Expenses:Materials General then that field will be left blank on import and will have to be set manually. Lines beginning with a # are regarded as comment lines and ignored.

The script is called with the following command:

`python importer.py file_to_import, invoice_id > file_to_save_as.csv`

This short script can easily be changed to suit any downloaded format. The only restriction is that the final number of field is fixed, at least at the moment. The importer will ignore lines with the wrong number of fields. (This may be fixed in future version). Vendor ID is simply the ID assigned to the specific vendor, or client. The row[N] items refer to the position in the line where the correct data lies. Note that the first field is row[0] NOT row[1].

Once you have converted the file navigate to Business Invoice & Bill Import to open a new import window. Select the file you have just created, select Bill or Invoice and Comma separated format. At this point the data should show up in the preview window. Check that the field data are in the correct columns before selecting OK. Once imported the invoice can be opened for editing and posting in the usual way.

A note on VAT, or any purchase tax. As previously mentioned Rapid Electronics calculate the VAT on the bill total not line by line. &app; calculated the VAT per line then totals the VAT. This can lead to inaccuracies in the VAT of the region of a few pennies and is enough to cause problems when reconciling the purchase with your bank or credit card account used to make the purchase. As to how you overcome that, for the moment, is a problem for you to use whatever method suits your conscience or accountant best. Personally I add the VAT as a separate line along with delivery charges manually. So some work is left to the user but the tedium of entering each item eliminated.

Future: Currently the import format is quite strict and many users may have problems with the conversion process. Adding a template for every possible vendor CSV format would be mammoth and likely impossible task notwithstanding the fact the vendors are likely to change the format without informing the &app; team. Future import enhancements will be based on user feedback and hopefully the process can be made simpler or more flexible. Note that often simple is incompatible with flexible.

If Python (other languages are avaialble) is not your thing then post a request to &app; user list, with an example of your downloaded CSV, and someone may write you a Python script to do the translation.

### Notes for Python authors

In order for the import to succeed the number of fields must be adhered to, so the trailing commas are important.

A complete list of the required fields is:

id, date_opened, owner_id, billingid, notes, date, desc, action, account, quantity, price, disc_type, disc_how, discount, taxable, taxincluded, tax_table, date_posted, due_date, account_posted, memo_posted, accu_splits,

Mind the trailing comma.

### A brief description of each field

- id - The invoice number. All lines must contain this or the line will be rejected.

- date_opened - Todays date is inserted if this is blank.

- owner_id - ID number of the vendor or customer. All lines must contain this or the line will be rejected.

- billingid - Billing ID.

- notes - Invoice notes.

- date - The date of the item line. Can be left blank for todays date.

- desc - Description as per normal invoice or bill.

- action - For bills usually ea.

- account - Account to which the item is attributed.

- quantity - Quantity of each item. Must contain a value or the line will be rejected.

- price - Price of each item. Must contain a value or the line will be rejected.

- disc_type - Type of discount, either % or TODO, only applies to invoices. Some experimentation may be required here as may be currency dependent.

- disc_how - Only applies to invoices.

- discount - Amount of discount to be applied. only applies to invoices.

- taxable - Will tax be applied to the item? y or blank.

- taxincluded - Is tax included in the item price? y or blank.

- tax_table - Tax table to apply to item.

- date_posted - If posted, what date. Normally left blank for manual posting after editing the invoice.

- due_date - Date payment is due.

- account_posted - Posted to what account.

- memo_posted - If posted insert memo here.

- accu_splits - Accumulate splits? y or blank.