> Why will this little program crash when you enter the > enter key? > > while True: > a = raw_input('number? ') > if a.isdigit(): > print 'isdigit' > elif a[0] == '-' and a[1:].isdigit():
You could instead use elif a.startswith('-') and a[1:].isdigit(): as the empty string certainly doesn't start with '-', and python won't check the second half after the first check evaluates false. > print '- + isdigit' > elif a == 'q': > break > else: > print 'no digit' _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor