file = loadFirst or self.my_askopenfilename()
if not file:
return

if not os.path.isfile(file):
showerror('PyEdit', 'Could not open file ' + file)
return

try known encoding if passed and accurate (e.g., email)

text = None # empty file = '' = False: test for None!
if loadEncode:
try:
text = open(file, 'r', encoding=loadEncode).read()
self.knownEncoding = loadEncode
except (UnicodeError, LookupError, IOError): # lookup: bad name
pass

try user input, prefill with next choice as default

if text == None and self.opensAskUser:
self.update() # else dialog doesn't appear in rare cases
askuser = askstring('PyEdit', 'Enter Unicode encoding for open',
initialvalue=(self.opensEncoding or
sys.getdefaultencoding() or ''))
if askuser:
try:
text = open(file, 'r', encoding=askuser).read()
self.knownEncoding = askuser
except (UnicodeError, LookupError, IOError):
pass

try config file (or before ask user?)

if text == None and self.opensEncoding:
try:
text = open(file, 'r', encoding=self.opensEncoding).read()
self.knownEncoding = self.opensEncoding
except (UnicodeError, LookupError, IOError):
pass

try platform default (utf-8 on windows; try utf8 always?)

if text == None:
try:
text = open(file, 'r', encoding=sys.getdefaultencoding()).read()
self.knownEncoding = sys.getdefaultencoding()
except (UnicodeError, LookupError, IOError):
pass

last resort: use binary bytes and rely on Tk to decode

if text == None:
try:
text = open(file, 'rb').read() # bytes for Unicode
text = text.replace(b'\r\n', b'\n') # for display, saves
self.knownEncoding = None
except IOError:
pass

702 | Chapter 11: Complete GUI Programs