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content/blog/python-argpase.md

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+---
+title: "Python Argument Parser"
+date: 2022-05-16T17:07:06-04:00
+draft: false
+tags: ["Python"]
+math: false
+---
+
+*For a much better description of argument parsing in Python, please visit https://docs.python.org/3/library/argparse.html.*
+
+I'm creating this post because even though it's not too complicated, I keep forgetting how to do argument parsing in Python. I also tricked myself into thinking each time that I already wrote a blog post on this. Let's correct this once and for all and include a quick example!
+
+```python
+import argparse
+parser = argparse.ArgumentParser(description="Description to show in help")
+parser.add_argument("pos_arg1", type=str, help="Required positional argument")
+parser.add_argument("--flag1", type=str, help="Optional flag argument")
+parser.add_argument("--flag2", type=int, required=True, help="Required flag argument")
+args = vars(parser.parse_args())
+```
+
+Now if you call the program with no arguments you'll get the following message:
+
+```
+usage: testarg.py [-h] [--flag1 FLAG1] --flag2 FLAG2 pos_arg1
+testarg.py: error: the following arguments are required: pos_arg1, --flag2
+```
+
+This comes with a built in `-h` as well!
+
+```
+usage: testarg.py [-h] [--flag1 FLAG1] --flag2 FLAG2 pos_arg1
+
+Description to show in help
+
+positional arguments:
+  pos_arg1       Required positional argument
+
+optional arguments:
+  -h, --help            show this help message and exit
+  --flag1 FLAG1         Optional flag argument
+  --flag2 FLAG2         Required flag argument
+```
+
+Within the code you can parse the argument names by accessing the `args` dictionary.
+
+```python
+pos_arg1 = args['pos_arg1']
+flag1 = args['flag1']
+flag2 = args['flag2']
+```
+
+
+