Error messages when reading .ecg file using PyECG packages

[vic22981106]

I was trying to read .ecg files from these 2 databases:

normal sinus rhythm RR interval database

congestive heart failure RR interval database

I've searched the Internet for a while and the only answer I got was to use the pyECG packages to read these .ecg files. But when I tried this code down below,
from pyecg import ECGRecord
ecg_path = "C:\\Users\\vince\\Desktop\\ECG database\\normal-sinus-rhythm-rr-interval-database-1.0.0\\nsr001.ecg"
record = ECGRecord.from_ishine(ecg_path)

error messages popped up!
Traceback (most recent call last):
File "<pyshell#16>", line 1, in <module>
record = ECGRecord.from_ishine(ecg_path)
File "C:\Users\vince\AppData\Local\Programs\Python\Python36\lib\site-packages\pyecg\ecg.py", line 168, in from_ishine return loader.load(ecg_file)
File "C:\Users\vince\AppData\Local\Programs\Python\Python36\lib\site-packages\pyecg\importers\ishine.py", line 68, in load record = Holter(ecg_file, check_valid=False)
File "C:\Users\vince\AppData\Local\Programs\Python\Python36\lib\site-packages\ishneholterlib\__init__.py", line 65, in __init__ self.load_header()
File "C:\Users\vince\AppData\Local\Programs\Python\Python36\lib\site-packages\ishneholterlib\__init__.py", line 123, in load_header self.var_block = get_val(filename, 522, 'a'+str(self.var_block_size)).split(b'\x00')[0]
File "C:\Users\vince\AppData\Local\Programs\Python\Python36\lib\site-packages\ishneholterlib\__init__.py", line 20, in get_val val = val[0]
IndexError: index 0 is out of bounds for axis 0 with size 0

By the way, the ecg file was download from the physionet database : Normal Sinus Rhythm RR Interval Database

I don't know what was going on when I got this error message. Can someone help me out?
Or is there any other package that I can use for the same purpose?