Maidenhead | Maidenhead Locator System is a geographic co

You have to call new L.Marker() or L.marker()

To fix your second error (in the comments) you have to define first your featureGroup and then create the markers.

Cliff's Notes for: https://en.wikipedia.org/wiki/Maidenhead_Locator_System

• Every pair characters in an MLS coordinate is a cell in a grid, with each subsequent grid contained inside the previous.
• Each pair alternates between alphabetical and numerical of bases: 18, 10, 24, GOTO 10 for as much precision as you feel like.
• While the spec says case is important, it's not really.

So we can decompose JO22OI60KE to (J,O), (2,2), (O,I), (6,0), (K,E) to (10,15), (2,2), (15,9), (6,0), (11,5).

The approach I took in the lib I wrote [included below] was to decompose the coordinates into their numeric pairs, and then apply any transformations [represented by a set of offsets] starting from the least significant to most while keeping a "carry" pair.

However, it would probably be simpler to just multiply everything out to an 259,200 x 259,200 [18*10*12*10*12] grid, do simple math to transform, and then use more math to reformat back to an MLS coordinate. This would also greatly simplify converting to/from lat/lng as that's just more simple math.

Live and learn. The first iteration of something is usually only good at teaching you how you should have done it. ¯\_(ツ)_/¯

Included because links can die which renders the answer useless. Please do check the repo in case there are PRs/changes. Also listed on Packagist,

Put print statements under each if statement and you will see that they are in fact running.

The problem is that once you iterate over the file object once, it reaches the end. The next time you iterate, it's already at the end and does nothing.

You either need to reset the file location, or close the file and read it again each time. Read the I/O section of the Python tutorial. https://docs.python.org/3/tutorial/inputoutput.html