Bash scripts are commonly used for automation, system administration, and task scheduling. However, Python can enhance Bash scripts by adding logic, working with APIs, and handling complex data structures. This guide explains how to integrate Python into Bash scripting.
1. Why Use Python in Bash Scripts?
Better Readability: Python code is easier to read and maintain.
Powerful Libraries: Python has libraries for APIs, databases, and data processing.
Cross-Platform Compatibility: Works on Windows, Linux, and macOS.
Automation: Python can automate complex workflows.
2. Running Python in Bash
2.1 Running a Python Script from Bash
If you have a Python script (script.py), you can execute it from Bash like this:
python3 script.py
or
./script.py # If the script is executable
Make the script executable:
chmod +x script.py
2.2 Using Python Inside a Bash Script
You can call Python within a Bash script:
#!/bin/bash
echo "Running Python Script from Bash"
python3 -c "print('Hello from Python!')"
Save it as script.sh, then run:
bash script.sh
3. Passing Arguments from Bash to Python
3.1 Example: Bash to Python Argument Passing
Bash script (run_python.sh)
#!/bin/bash
name="Narendra"
age=25
python3 script.py "$name" "$age"
Python script (script.py)
import sys
name = sys.argv[1] # First argument
age = sys.argv[2] # Second argument
print(f"Hello {name}, you are {age} years old!")
Run the Bash script:
bash run_python.sh
4. Executing Bash Commands in Python
4.1 Using subprocess Module
Python’s subprocess module allows running shell commands.
import subprocess
# Run ls command
output = subprocess.run(["ls", "-l"], capture_output=True, text=True)
print(output.stdout)
4.2 Running Bash Commands and Capturing Output
import subprocess
command = "echo Hello, World!"
output = subprocess.check_output(command, shell=True, text=True)
print("Bash Output:", output)
5. Writing Hybrid Bash-Python Scripts
5.1 Embedding Python in Bash Scripts
Bash allows using Python code inside a script using Here Document (EOF).
#!/bin/bash
echo "Calculating Sum using Python"
sum=$(python3 <<EOF
a = 10
b = 20
print(a + b)
EOF
)
echo "The sum is: $sum"
Run the script:
bash script.sh
6. Automating Tasks with Python and Bash
6.1 Example: Automating File Backup
Bash script (backup.sh)
#!/bin/bash
backup_dir="backup_$(date +%Y%m%d)"
mkdir -p $backup_dir
python3 <<EOF
import shutil
shutil.make_archive("$backup_dir", 'zip', ".")
print("Backup created: $backup_dir.zip")
EOF
Run:
bash backup.sh
7. Scheduling Python Scripts Using Cron Jobs
7.1 Setting Up a Cron Job
Use crontab -e to add a job that runs script.py every day at 5 AM:
0 5 * * * /usr/bin/python3 /path/to/script.py
List scheduled jobs:
crontab -l