Exception when encoding a single character

[foozmeat]

version, level, qr_name = myqr.run(
        'A',
        level='H',
        colorized=False,
        contrast=1.0,
        brightness=1.0,
        save_name='testing.png',
        save_dir='barcodes'
)

Traceback (most recent call last):
  File "/.ta_venv/lib/python3.6/site-packages/MyQR/myqr.py", line 94, in run
    ver, qr_name = theqrmodule.get_qrcode(version, level, words, tempdir)
  File "/.ta_venv/lib/python3.6/site-packages/MyQR/mylibs/theqrmodule.py", line 10, in get_qrcode
    ver, data_codewords = data.encode(ver, ecl, str)
  File "/.ta_venv/lib/python3.6/site-packages/MyQR/mylibs/data.py", line 18, in encode
    code = mode_indicator[mode] + get_cci(ver, mode, str) + mode_encoding[mode](str)
  File "/.ta_venv/lib/python3.6/site-packages/MyQR/mylibs/data.py", line 84, in alphanumeric_encoding
    if i != len(code_list) - 1:
UnboundLocalError: local variable 'i' referenced before assignment