dideler · August 17, 2025 06:15 · Nov 30, 2018 · Apr 6, 2013 · Dec 21, 2012 · Jul 11, 2012
diff --git a/pyargs.md b/pyargs.md
@@ -2,35 +2,41 @@ Command-line arguments in Python show up in `sys.argv` as a list of strings (so
 
 For example, if you want to print all passed command-line arguments:
 
-    import sys
-    print(sys.argv)  # Note the first argument is always the script filename.
+```python
+import sys
+print(sys.argv)  # Note the first argument is always the script filename.
+```
 
 Command-line options are sometimes passed by position (e.g. `myprogram foo bar`) and sometimes by using a "-name value" pair (e.g. `myprogram -a foo -b bar`).
 
 Here's a simple way to parse command-line pair arguments. It scans the `argv` list looking for `-optionname optionvalue` word pairs and places them in a dictionary for easy retrieval. The code is heavily commented to help Python newcomers.
 
-    """Collect command-line options in a dictionary"""
-
-    def getopts(argv):
-        opts = {}  # Empty dictionary to store key-value pairs.
-        while argv:  # While there are arguments left to parse...
-            if argv[0][0] == '-':  # Found a "-name value" pair.
-                opts[argv[0]] = argv[1]  # Add key and value to the dictionary.
-            argv = argv[1:]  # Reduce the argument list by copying it starting from index 1.
-        return opts
-
-    if __name__ == '__main__':
-        from sys import argv
-        myargs = getopts(argv)
-        if '-i' in myargs:  # Example usage.
-            print(myargs['-i'])
-        print(myargs)
+```python
+"""Collect command-line options in a dictionary"""
+
+def getopts(argv):
+    opts = {}  # Empty dictionary to store key-value pairs.
+    while argv:  # While there are arguments left to parse...
+        if argv[0][0] == '-':  # Found a "-name value" pair.
+            opts[argv[0]] = argv[1]  # Add key and value to the dictionary.
+        argv = argv[1:]  # Reduce the argument list by copying it starting from index 1.
+    return opts
+
+if __name__ == '__main__':
+    from sys import argv
+    myargs = getopts(argv)
+    if '-i' in myargs:  # Example usage.
+        print(myargs['-i'])
+    print(myargs)
+```
 
 Running this script:
 
-    $ python main.py -i input.txt -o output.txt
-    input.txt
-    {'-o': 'output.txt', '-i': 'input.txt'}
+```shell
+$ python main.py -i input.txt -o output.txt
+input.txt
+{'-o': 'output.txt', '-i': 'input.txt'}
+```
 
 Simple solution, but not very robust; it doesn't handle error checking and the like. So don't use this in production code! There are more complex alternatives available. Some modules to consider are:
 

diff --git a/pyargs.md b/pyargs.md
@@ -35,7 +35,8 @@ Running this script:
 Simple solution, but not very robust; it doesn't handle error checking and the like. So don't use this in production code! There are more complex alternatives available. Some modules to consider are:
 
 * `getopt`
-* `optparse` (deprecated)
-* `argparse` (recommended)
+* `optparse` (deprecated since Python 2.7)
+* `argparse` (recommended if you want something in the standard library)
+* [`docopt`](http://docopt.org/) (recommended if you're willing to use something not in the standard library)
 
 This post was inspired by the book "Programming Python" by Mark Lutz.
diff --git a/pyargs.md b/pyargs.md
@@ -36,6 +36,6 @@ Simple solution, but not very robust; it doesn't handle error checking and the l
 
 * `getopt`
 * `optparse` (deprecated)
-* `argparse`
+* `argparse` (recommended)
 
 This post was inspired by the book "Programming Python" by Mark Lutz.
diff --git a/pyargs.md b/pyargs.md
@@ -12,11 +12,11 @@ Here's a simple way to parse command-line pair arguments. It scans the `argv` li
     """Collect command-line options in a dictionary"""
 
     def getopts(argv):
-        opts = {}  # Empty dictionary.
-        while argv:  # While there are arguments left to parse.
+        opts = {}  # Empty dictionary to store key-value pairs.
+        while argv:  # While there are arguments left to parse...
             if argv[0][0] == '-':  # Found a "-name value" pair.
                 opts[argv[0]] = argv[1]  # Add key and value to the dictionary.
-            argv = argv[1:]  # Reduce the argument list.
+            argv = argv[1:]  # Reduce the argument list by copying it starting from index 1.
         return opts
 
     if __name__ == '__main__':

diff --git a/pyargs.md b/pyargs.md
@@ -16,9 +16,7 @@ Here's a simple way to parse command-line pair arguments. It scans the `argv` li
         while argv:  # While there are arguments left to parse.
             if argv[0][0] == '-':  # Found a "-name value" pair.
                 opts[argv[0]] = argv[1]  # Add key and value to the dictionary.
-                argv = argv[1:]  # Reduce the argument list.
-            else:
-                argv = argv[1:]
+            argv = argv[1:]  # Reduce the argument list.
         return opts
 
     if __name__ == '__main__':

diff --git a/pyargs.md b/pyargs.md
@@ -3,7 +3,7 @@ Command-line arguments in Python show up in `sys.argv` as a list of strings (so
 For example, if you want to print all passed command-line arguments:
 
     import sys
-    print(sys.argv)
+    print(sys.argv)  # Note the first argument is always the script filename.
 
 Command-line options are sometimes passed by position (e.g. `myprogram foo bar`) and sometimes by using a "-name value" pair (e.g. `myprogram -a foo -b bar`).
 
@@ -28,12 +28,16 @@ Here's a simple way to parse command-line pair arguments. It scans the `argv` li
             print(myargs['-i'])
         print(myargs)
 
-Running this script (note the first argument is always the script filename):
+Running this script:
 
     $ python main.py -i input.txt -o output.txt
     input.txt
     {'-o': 'output.txt', '-i': 'input.txt'}
 
-Simple solution, but not very robust; it doesn't handle error checking and the like. So don't use this in production code! There are more complex alternatives available. Some modules to consider are `getopt`, `optparse` (deprecated), and `argparse`.
+Simple solution, but not very robust; it doesn't handle error checking and the like. So don't use this in production code! There are more complex alternatives available. Some modules to consider are:
+
+* `getopt`
+* `optparse` (deprecated)
+* `argparse`
 
 This post was inspired by the book "Programming Python" by Mark Lutz.
diff --git a/pyargs.md b/pyargs.md
@@ -0,0 +1,39 @@
+Command-line arguments in Python show up in `sys.argv` as a list of strings (so you'll need to import the `sys` module).
+
+For example, if you want to print all passed command-line arguments:
+
+    import sys
+    print(sys.argv)
+
+Command-line options are sometimes passed by position (e.g. `myprogram foo bar`) and sometimes by using a "-name value" pair (e.g. `myprogram -a foo -b bar`).
+
+Here's a simple way to parse command-line pair arguments. It scans the `argv` list looking for `-optionname optionvalue` word pairs and places them in a dictionary for easy retrieval. The code is heavily commented to help Python newcomers.
+
+    """Collect command-line options in a dictionary"""
+
+    def getopts(argv):
+        opts = {}  # Empty dictionary.
+        while argv:  # While there are arguments left to parse.
+            if argv[0][0] == '-':  # Found a "-name value" pair.
+                opts[argv[0]] = argv[1]  # Add key and value to the dictionary.
+                argv = argv[1:]  # Reduce the argument list.
+            else:
+                argv = argv[1:]
+        return opts
+
+    if __name__ == '__main__':
+        from sys import argv
+        myargs = getopts(argv)
+        if '-i' in myargs:  # Example usage.
+            print(myargs['-i'])
+        print(myargs)
+
+Running this script (note the first argument is always the script filename):
+
+    $ python main.py -i input.txt -o output.txt
+    input.txt
+    {'-o': 'output.txt', '-i': 'input.txt'}
+
+Simple solution, but not very robust; it doesn't handle error checking and the like. So don't use this in production code! There are more complex alternatives available. Some modules to consider are `getopt`, `optparse` (deprecated), and `argparse`.
+
+This post was inspired by the book "Programming Python" by Mark Lutz.