Improve variant comparison

[smlmbrt]

Find a better way to handle this, the try/except patter seems to throw an error:

fraposa_pgsc/fraposa_pgsc/fraposa.py

Lines 523 to 529 in 4901a20

	try:
	variants: Variants = compare_variants(ref_variants=X_bim, study_variants=W_bim)
	except NameError:
	with open(ref_filepref + '_vars.dat', 'r') as infile:
	ref_vars = infile.read().strip().split('\n')
	stu_vars = bim_varlist(W_bim)
	variants: Variants = compare_variants(ref_variants=ref_vars, study_variants=stu_vars)

Error:

Traceback (most recent call last):
  File "/venv/lib/python3.10/site-packages/fraposa_pgsc/fraposa.py", line 524, in pca
    variants: Variants = compare_variants(ref_variants=X_bim, study_variants=W_bim)
UnboundLocalError: local variable 'X_bim' referenced before assignment

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/venv/bin/fraposa", line 8, in <module>
    sys.exit(main())
  File "/venv/lib/python3.10/site-packages/fraposa_pgsc/fraposa_runner.py", line 56, in main
    fp.pca(ref_filepref=ref_filepref, stu_filepref=stu_filepref, stu_filt_iid=stu_filt_iid, out_filepref=out_filepref,
  File "/venv/lib/python3.10/site-packages/fraposa_pgsc/fraposa.py", line 529, in pca
    variants: Variants = compare_variants(ref_variants=ref_vars, study_variants=stu_vars)
  File "/venv/lib/python3.10/site-packages/fraposa_pgsc/fraposa.py", line 191, in compare_variants
    stu_indexed: list[int] = [ref_indexed[variant] for variant in stu_vars]
  File "/venv/lib/python3.10/site-packages/fraposa_pgsc/fraposa.py", line 191, in <listcomp>
    stu_indexed: list[int] = [ref_indexed[variant] for variant in stu_vars]
KeyError: '1:255633:A:G'