Correctly reading text from Windows-1252(cp1252) file in python

CP1252 cannot represent ā; your input contains the similar character â. repr just displays an ASCII representation of a unicode string in Python 2.x:

>>> print(repr(b'J\xe2nis'.decode('cp1252')))
u'J\xe2nis'
>>> print(b'J\xe2nis'.decode('cp1252'))
Jânis

I think u'J\xe2nis' is correct, see:

>>> print u'J\xe2nis'.encode('utf-8')
Jânis

Are you getting actual errors from SQLAlchemy or in your application's output?