Appending string to list adds a '\r' to every element

Question

I am trying to append a string to a list (seqs). The strings look something like random letters which I am reading line by line from a file. Printing out the string shows no sign of a '\r'. But printing out the list does.

   seqs.append(seq)
   print('seq is', seq)

gives: seq is CSMKMTIGSGTKTLHRWAFNPTQQTCVTFVYTGAAGNQNNFLTRNDCVNTC

   print(seqs)

gives: 'CSMKMTIGSGTKTLHRWAFNPTQQTCVTFVYTGAAGNQNNFLTRNDCVNTC\r'

I have tried changing the file a few different ways, even writing an example file of just lines of text so I am fairly certain I am not adding a '\r' to the file. Any help would be much appreciated.

Edit: I printed the sequence differently and I do see the carriage return now. Is there anyway I can remove it? For now when I parse through the sequences I just say if it's '\r' continue. To skip it

It's reading a gzip file and opening it with:

with gzip.open(filepath, 'rb') as fin: 
    file_content = fin.read().decode(encoding)
    lines = file_content.split('\n')
    for line in lines: #separate them into a list

EDIT EDIT I just did file_content.split('\r\n')...Seemed to fix the problem, not sure why I did not think of it sooner. Thanks everyone!