Pass variable to python script
Running Python scripts from the command line can be a great way to automate your workflows. To do this, you’ll need to learn how to pass arguments from the command line to a Python script. This will allow you to create reusable scripts that can be updated, or run for new situations or data by just passing in a couple of new arguments. In Python getting arguments from the command line to a script is quite easy. Show Before you can pass arguments to a script, you’ll need to understand how to run a Python script from the command line. Follow this tutorial for a step-by-step guide. In Python, arguments are passed to a script from the command line using the Let’s go through some examples. To start, we’ll create a script that prints out the entire command line statement. Then we can examine how the arguments are passed and learn how to incorporate those into our code. In the Python script, we’ll import
Save this script as You’ll notice when I call the script that I’ve
included three arguments separated by a space (arg1, arg2, and arg3). These are just to illustrate how Here’s my call to
You can see that Here’s the script call and output.
As you can see, the float and integer were also stored as strings by Accessing Command Line Arguments in a Python ScriptNow that we have some basic information about how to access command-line arguments and how they are stored, we can start parsing those arguments for use in our script. In this simple example, we’ll iterate through each argument (except the first one, which is the script name) and print it to the console. Let’s start by updating the Python script, Here’s the new script. Notice that we iterate through a
Run the script using the last set of arguments. Like this.
You should get output that looks like this.
That gives you the basics of passing command-line arguments to a Python script. From here, you’ll probably want to do some logical checks to make sure the input values are the appropriate types and fall within the correct range or set of values. Improved Parsing of Python Command Line ArgumentsThe examples above provide simple examples to get you started. However, if you’re looking for something more advanced that allows users to specify arguments with keywords and print help messages we’ll need to get a little more advanced. To retrieve named arguments from the command line we’ll use Python’s Let’s start a new script that uses both This script will consist of two parts. The first part is a function ( In the body of Now
call I’ve put the call to
In the final part of the script, we’ll parse the arguments based on their short or long names, or keywords, and print out the final values. To start, loop through all the elements of The final script should look similar to this.
Let’s use this script in a couple of different ways to see what happens. First, let’s get the help message using both the short
As expected, both examples resulted in the help message printing to the console. Next, let’s see what happens if we specify an invalid argument name,
This caused an error, which resulted in the help message printing to the console again. Now, let’s enter the correct arguments.
The arguments were assigned to the appropriate variables. Next StepsThis article gives you a primer on passing and parsing command line arguments with Python. For a full-fledged implementation, there is still more work you will want to do. It will be important to check the types and values of the input arguments to be sure they are valid. You’ll also want to make sure to print out helpful messages to the user when an error or other exception occurs. If you’re just implementing this for personal use, those features aren’t so important. I’ve found that writing my Python scripts to run from the command line has helped me automate many of my tasks and analyses and has saved me lots of time. Learn GIS From Industry ProfessionalsWhether you’re looking to take your GIS skills to the next level, or just getting started with GIS, we have a course for you! We’re constantly creating and curating more courses to help you improve your geospatial skills. All of our courses are taught by industry professionals and include step-by-step video instruction so you don’t get lost in YouTube videos and blog posts, downloadable data so you can reproduce everything the instructor does, and code you can copy so you can avoid repetitive typing How do you pass a variable in a Python script?How to pass information to a Python script using the sys. argv command by hard-coding the input variables in Jupyter Notebook or through the interactive use of the input() function.
How do I pass a command line argument to a Python script?script name.. Example. Consider the following script test.py − #!/usr/bin/python import sys print 'Number of arguments:', len(sys. ... . Parsing Command-Line Arguments. Python provided a getopt module that helps you parse command-line options and arguments. ... . getopt. getopt method. ... . Exception getopt. GetoptError.. |