Tried json->tab of an already made json but got this error and a 0 bytes .tab file

[Musrar]

As per said in the title, I tried running yomi2tab.py on an already created json (specifically a korean-japanese one) and got this, on Linux 20.03:

$ python3 yomi2tab.py -o ko-jadict.tab yomi_output/
Processing files: 0%| | 0/1 [00:00<?, ?file/s]/home/musrar/Documents/korean dict/epwing2kindle-master/yomi2tab.py:90: FutureWarning: Series.getitem treating keys as positions is deprecated. In a future version, integer keys will always be treated as labels (consistent with DataFrame behavior). To access a value by position, use ser.iloc[pos]
if '―' in row[0]:
Processing files: 100%|█████████████████████████| 1/1 [03:48<00:00, 228.24s/file]
Traceback (most recent call last):
File "/home/musrar/Documents/korean dict/epwing2kindle-master/yomi2tab.py", line 229, in
result = process_folder(args.folder, simplify=args.simplify)
File "/home/musrar/Documents/korean dict/epwing2kindle-master/yomi2tab.py", line 169, in process_folder
result.replace('', pd.np.nan, inplace=True)
AttributeError: module 'pandas' has no attribute 'np'

The result was a 0 bytes "koja-dict.tab"
I could provied the .json file if needed be.