Calling Python from bash: Difference between revisions

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Also see: {{Internal|Python_Language_Modularization#Python_Script|Python Script}}
Also see: {{Internal|Python_Language_Modularization#Python_Script|Python Script}}
=Code in External Script=
==External Script==
==External Module==
Given an external module <code>my_module.py</code> with the following content:
<syntaxhighlight lang='python'>
def my_function(arg1, arg2, arg3):
    print('this is my_function(' + arg1 + ", " + arg2 + ", " + arg3 + ")")
</syntaxhighlight>
the module can be called generically from a bash script as follows:
<syntaxhighlight lang='bash'>
#!/usr/bin/env bash
function call-python() {
  local python_interpreter=$1
  local module_path=$2
  local function_name=$3
  [[ -z ${python_interpreter} ]] && fail "'python_interpreter' not provided"
  [[ -z ${module_path} ]] && fail "'module_path' not provided"
  [[ -z ${function_name} ]] && fail "'function_name' not provided"
  shift 3
  local args
  for i in "${@}"; do
    [[ -z ${args} ]] && args="'${i}'" || args="${args}, '${i}'"
  done
  local module_name
  module_name=$(basename "${module_path}" .py)
  # instead of PATH python3 you may want to use the interpreter from a specific virtual environment
  (PYTHONPATH="$(dirname ${module_path})"; export PYTHONPATH; ${python_interpreter} <<EOF
import ${module_name}
${module_name}.${function_name}(${args})
EOF
  )
}
call-python ./my_module.py my_function blue red green
</syntaxhighlight>
The output will be:
<syntaxhighlight lang='text'>
this is my_function(blue, red, green)
</syntaxhighlight>
⚠️ <Font color=darkkhaki>Numbers will be converted to strings before being passed to the function, the implementation is incomplete.</font>


=Using the Interpreter from the a Virtual Environment=
=Using the Interpreter from the a Virtual Environment=

Revision as of 16:47, 2 May 2023

Internal

Overview

Inline Python Code

Use bash here-doc: 

  python3 <<EOF
print('blah')
EOF

Also see:

Python Script

Using the Interpreter from the a Virtual Environment

If you want to use the interpreter from a specific virtual environment instead of the interpreter found in PATH, explicitly use the path to the binary from the virtual environment directory: 

$(dirname $0)/venv/bin/python ...

Running a Python Program with a Bash Wrapper

Check out these links for the meaning of standalone Python program and Python script.

Bash to Python Function Mapping

Bash to Python Function Mapping
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