There are five ways you can execute your Python script on macOS.
As you already know,
you can execute your Python script in IDLE
by pulling down
Run → Run Module
First find out where the executable file
python3
was installed on your Mac.
Launch
Applications → Utilities → Terminal.app
and say
which python3 /Library/Frameworks/Python.framework/Versions/3.6/bin/python3 exit
Now launch
Applications → Python 3.6 → Python Launcher.app
In the Preferences window, say
Settings for file type: Python Script
Interpreter:
/Library/Frameworks/Python.framework/Versions/3.6/bin/python3
☑ Run in a terminal window
Then quit the Python Launcher.
You should now be able to launch your Python script
in the macOS Finder by dragging the script onto the Python Launcher.
A Terminal window will open,
in which your Python program will run.
The window will even display the exit status (zero) you passed to the
sys.exit
function.
Select your Python script in the macOS finder, and type
command-i
for information about it.
In the Info window,
under
▼ Open with:
select Python Launcher 3.app (3.6.4).
You should now be able to launch your Python script by double-clicking on the script in the macOS Finder.
python3
Launch
Applications →
Utilities →
Terminal.app
If you are already in the directory that holds your Python script,
you can simply give the name of the script to
python3.
(If you don’t know what directory that is,
search for it with
find
and wait patiently.)
If you are in a different directory,
you can still run your script but you’ll have to tell
python3
where your script is.
which python3 /Library/Frameworks/Python.framework/Versions/3.6/bin/python3 find / -type f -name inout.py 2> /dev/null /Users/myname/python/inout.py cd /Users/myname/python pwd /Users/myname/python python3 inout.py What is your first name? python3 /Users/myname/python/inout.py What is your first name?
Edit the script (using IDLE or TextEdit.app)
so that its first line is
#!/usr/bin/env python3
The first two characters on the first line must be
#!
And if you’re using a fancy editor,
make sure you save the file as plain text, not rich text.
It should look like this:
#!/usr/bin/env python3
"""
inout.py
Prompt the user for their age.
Then tell them how old they are in dog years.
"""
import sys
try:
years = input("How old are you? ")
#etc.
Launch
Applications → Utilities → Terminal.app
and
cd
to the directory that holds your script.
Use
chmod
to turn on the script’s
r
and
x
bits to make it readable and executable.
cd /Users/myname/python pwd /Users/myname/python ls -l inout.py -rw-r--r--@ 1 myname mygroup 448 Jun 8 17:29 inout.py chmod 755 inout.py ls -l inout.py -rwxr-xr-x@ 1 myname mygroup 448 Jun 8 17:29 inout.py ./inout.py How old are you?
The leading
./
tells the
bash
shell to execute the
inout.py
that’s in the user’s current directory.
./
You can eliminate the need for the
./
by placing the
inout.py
in a directory that’s in your
PATH.
For example, I created a folder (directory) named
/Users/myname/python
and that’s where I put my Python programs.
To see the directories that are already in your
PATH,
echo $PATH
/Library/Frameworks/Python.framework/Versions/3.6/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin
echo $PATH | tr : '\n'
/Library/Frameworks/Python.framework/Versions/3.6/bin
/usr/local/bin
/usr/bin
/bin
/usr/sbin
/sbin
/opt/X11/bin
echo $PATH | tr : '\n' | cat -n
1 /Library/Frameworks/Python.framework/Versions/3.6/bin
2 /usr/local/bin
3 /usr/bin
4 /bin
5 /usr/sbin
6 /sbin
7 /opt/X11/bin
When you installed Python 3 on your Mac,
you automatically appended the following two statements to the
.bash_profile
file in your home directory.
If you are confident in your ability to edit your
.bash_profile
without damaging it,
you can edit this file with
Applications → TextEdit.app
When TextEdit shows you the names of the files in your home directory,
press command-shift->
to see the files whose names start with a dot.
Then double-click on
.bash_profile.
The last two statements in
.bash_profile
should be
# Setting PATH for Python 3.6
# The original version is saved in .bash_profile.pysave
PATH="/Library/Frameworks/Python.framework/Versions/3.6/bin:${PATH}"
export PATH
Change them to
# Setting PATH for Python 3.6
# The original version is saved in .bash_profile.pysave
PATH="/Library/Frameworks/Python.framework/Versions/3.6/bin:${HOME}/python:${PATH}"
export PATH
You should now be able to open a Terminal window and say
echo $PATH | tr : '\n' | cat -n
1 /Library/Frameworks/Python.framework/Versions/3.6/bin
2 /Users/myname/python
3 /usr/local/bin
4 /usr/bin
5 /bin
6 /usr/sbin
7 /sbin
8 /opt/X11/bin
which inout.py
/Users/myname/python/inout.py
inout.py
How old are you?