On Fri, Oct 10, 2014 at 2:05 AM, Wolfgang Maier <wolfgang.ma...@biologie.uni-freiburg.de> wrote: > On 10/10/2014 05:57 AM, boB Stepp wrote: >> >> I am hoping to save other people the grief I just worked through. I >> wanted to run both Python 2 and 3 on my windows PC, and, after >> googling this topic found that with Python 3.3 or later one could >> easily do both. So I merrily installed Python 3.4.2 first and then >> Python 2.7.8. A Python 3 program that had been working fine suddenly >> stopped working. After working down to a test portion of code that >> isolated the culprit I realized my Python 3 program was being >> interpreted by Python 2. > > > It would help if you could share details about how you tried to run the > Python 3 program (command line call, double-click, Python launcher for > Windows, ..). > Initially, I ran the program in question by double-clicking on its icon, which was my normal way of running it. This is when I realized I had a problem. The program would run without error, but give erroneous print and input statement results. I next put Python 3 into my path variable, but the same error persisted. From the command line I found that if I ran it normally (With Python 3 still in the path like it was on my previous 3.4.1 installation.), meaning
python program_name.py it behaved the same way as double-clicking on the icon. However, if I ran it as py -3 program_name.py then all was well. Apparently Python 2.7.8 became the system default installation if I installed it last, but after uninstalling both and installing Python 3.4.2 last, it became the default. Or, at least when double-clicked on it ran normally. I have since added shebang lines to my programs specifying Python 3. I hope I have not forgotten any relevant details! -- boB _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
