Environment variables

Database creation


ProjPicker needs to know where the PROJ database file proj.db is to be able to extract necessary information and create its own projpicker.db database file. PROJ_DB can be used to specify the full path to proj.db. However, since the ProjPicker github repository and its PyPI package already provide a projpicker.db created from pyproj 3.1.0, this variable is only needed when one wants to recreate it for some reason.


This variable is defined by PROJ to locate its proj.db database file. By definition, it is PROJ_DB less the filename part /proj.db or the dirname part of PROJ_DB. ProjPicker uses this variable only when PROJ_DB is not defined. Again, this variable is only useful when a new projpicker.db needs to be created.

General usage


This variable can be used to locate projpicker.db when it is not in the default location with the ProjPicker module. It can also be used when a new projpicker.db is created. In most cases, it should be not needed.


The GUI and standalone web server support verbose message printing mainly for debugging purposes. If this variable is set to YES, debugging messages are printed to stderr.



ProjPicker implements the wxPython-based and tkinter-based GUIs. If this variable is set to tk or the wxPython module is not availble, the tkinter-based GUI is used.


This variable is used to set the initial latitude and longitude for the GUI. Its coordinates must be in parsable coordinate formats. If it is not set, latitude 0 and longitude 0 are used. If the latitude is less than -85.0511, the minimum latitude supported by OpenStreetMap, -85.0511 is used. If it is greater than the maximum supported latitude 85.0511, 85.0511 is used. Similarly, if the longitude is less than -180 or greater than 180, -180 or 180 is used respectively.


This integer varaible is used to set the initial zoom level for the GUI. If it is not set or outside 0 and 18, which are the minimum and maximum zoom levels supported by OpenStreetMap, 0 is used.


The mouse wheel usually provides clicking feedback when scrolled, so it feels natural when a zoom event takes place per scroll. However, TrackPoint lacks such feedback and one can easily produce too many zoom events in a short period of time. This variable can be used to control the sensitivity of the mouse wheel or TrackPoint for zooming, called the delta zoom level or dzoom. For the mouse wheel, the default dzoom of 1 works perfectly fine. For the TrackPoint, a dzoom of 0.1 is recommended for better zooming experience.