gfonts-2-filter-fonts-get-paths.py

def filter_fonts_get_paths(df, root='./', variants=['_'], subsets=['_'], category=''):
    # exceptions
    if not variants or variants == [''] or variants == '': variants = ['_']
    if not subsets or subsets == [''] or subsets == '': subsets = ['_']
    # apply filters
    regex_filters = variants + subsets + ['_'+category]
    df_new = pd.concat([df.filter(regex=re.compile(regex, re.IGNORECASE), axis=1).sum(axis=1).astype(bool) for regex in regex_filters], axis=1)
    mask = df_new.all(axis=1)
    filtered_fontnames = list(df.loc[mask].family)
    
    # construct file paths
    paths = []
    for fontname in filtered_fontnames:
        if variants == ['_']: # select all variants
            sel = glob.glob(f'{root}/{fontname.lower()}/**/*.ttf', recursive=True)
            paths.extend(sel)
        else:
            for variant in variants:
                sel = glob.glob(f'{root}/{fontname.lower()}/**/{fontname}-{variant}.ttf', recursive=True) 
                for path in sel:
                    paths.append(path)
    print(f'Found {len(paths)} font files.')
    return paths

# let's try the function
paths = filter_fonts_get_paths(df, root=ROOT, subsets=['latin'], variants=['thinitalic'], category='sans-serif')