Make sure you are in the correct working directory after opening the terminal. A type
cd /Users/billp/Documents/
(use the tab for autocomplete)
then
python ./script1.py
python . shebang #! script , : ./script1.py, chmod +x script1.py (python) shebang. #!/usr/bin/env python python .
./ . , script1.py ( , ), , PATH env. script1.py , -bash: script1.py: command not found. python, , PATH, .