Hallo all,
that is well done work!!
To explain my annotations, at first some words about me. I stopped coding (Pascal) in 1995 (my fault

). All the time since 1982 I worked as a designer for tool machines. Freecad I joined 2014 for testing, Now I attend to use it for a small private project. Now my questions:
Is it possible to have an axis (datum) in that features that could be shown in TechDraw later and that could be used as reference for positioning screws in a future assembly? I don't see any... (may be I have to change some properties)
I think that it should be better to collect the standard informations (as in Standard.py) in a file like a LibreOfficeCalc-document or anything similar. When changing the standard it could be easier tu update such a file than code-lines. Otherwise than it could be possible (with some rules for naming that files) to implement "user-specific" files for non-standard holes or even factory-specific holes. What do you think about that.
At least a small hint: Row3 as in DIN 974-1:1991-05 is deleted in DIN 974-1:2008-02, because DIN 7980 "Federringe für Zylinderschrauben" is not valid any more. How should we handle this?
Andreas
OS: Ubuntu 16.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.9663 (Git)
Build type: Unknown
Branch: FeatureHole
Hash: f4fab7c79b002aa96e97c27c2dd0b9f19b6af3dc
Python version: 2.7.12
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17