Calling Python from bash: Difference between revisions

From NovaOrdis Knowledge Base
Jump to navigation Jump to search
Line 22: Line 22:
def my_function(arg1, arg2, arg3):
def my_function(arg1, arg2, arg3):
     print('this is 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 module_path=$1
  local function_name=$2
  local arg1=$3
  local arg2=$4
  local arg3=$5
  local module_name
  module_name=$(basename "${module_path}" .py)
  (PYTHONPATH="$(dirname ${module_path})"; export PYTHONPATH; python3 <<EOF
import ${module_name}
${module_name}.${function_name}('${arg1}', '${arg2}', '${arg3}')
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>
</syntaxhighlight>



Revision as of 23:57, 15 February 2022

Internal

Overview

Inline Python Code

Use bash here-doc:

  python3 <<EOF
print('blah')
EOF

Also see:

Python Script

Code in External Script

External Script

External Module

Given an external module my_module.py with the following content:

def my_function(arg1, arg2, arg3):
    print('this is my_function(' + arg1 + ", " + arg2 + ", " + arg3 + ")")

the module can be called generically from a bash script as follows:

#!/usr/bin/env bash

function call-python() {
  local module_path=$1
  local function_name=$2
  local arg1=$3
  local arg2=$4
  local arg3=$5
  local module_name
  module_name=$(basename "${module_path}" .py)
  (PYTHONPATH="$(dirname ${module_path})"; export PYTHONPATH; python3 <<EOF
import ${module_name}

${module_name}.${function_name}('${arg1}', '${arg2}', '${arg3}')
EOF
  )
}

call-python ./my_module.py my_function blue red green

The output will be:

this is my_function(blue, red, green)

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 ...