Python version 3 that seems to be ignored by the system on a Raspberry Pi

[Discret68]

Hello everyone

I am writing to you from France. My english is really basic

I recently bought a Raspberry Pi 3 model B. I am under Rasbian version 9, updated today.
I installed python3 in addition to the original python2. A python3 command via the console confirms me a version 3.5.3.
In the various programs that I just wrote in python, I start with the shebang "#! / Usr / bin / env python3" which launches the use of version 3 of python.
I realized at launch of my programs that the syntaxes corresponding to python 3 generate errors.

For example, when I call tkinter with the syntax python 3 "import tkinter", I get the following error message "import tkinter ImportError: No module named tkinter"

When I use the python 2 syntax "import Tkinter", everything happens normally.

If in a program in python, after the shebang python 3, I run the command "sys.version_info [0]", I get the value 2 while I should have the value 3.

As a first approach, I would say that python 3 is as ignored, or not recognized by the system.

I looked in the directory / usr / bin and I found the different files related to python 3 and 3.5 (python3, python3-config, python3m, python3m-config, python3.5, python3.5-config, python3.5m, python3.5m-config).

Being still very new to this structure, I do not know which syntax to use for the Unix command to use. I did some tests with different syntaxes (eg #! / Usr / bin / env python3, #! / Usr / bin / env python3.5) plus the same with the prefix "env" (#! / Usr / bin / env python3, #! / usr / bin / env python3.5), but to no avail.

I told myself that tkinter was not installed on my RPI. I launched the command "sudo apt-get install python3-tk" but I have a message that tells me that tkinter is already installed!

Would anyone have advice to me to understand what is happening in order to effectively use python 3 on my RPI?

Many thanks to you
JP

[Gribouillis]

There should be no space characters in /usr/bin/env. Try with

#!/usr/bin/env python3

It needs to be the first line of the file. You can also try #!/usr/bin/python3

[Discret68]

Hi Gribouillis

It's google translate that added the spaces during the translation for this message. In reality, there is no space and this syntax does not work.

JP

[Gribouillis]

From what I read here, the error could be that your file has Windows line endings. You can install the dos2unix command to convert it to Unix/Linux line endings and retry.