diff --git a/git-open b/git-open
index 30f36280390e077815dad40b19b4a18d8acb8381..b175a7a06d2d8f9716da61e11adf30be059b345b 100755
--- a/git-open
+++ b/git-open
@@ -1,15 +1,34 @@
 #!/usr/bin/env python3
 
+"""Figure out the HTTP source of a remote, and open it in a browser."""
+
 import sys
 import subprocess
 import argparse
 import re
 import os.path
+
+
+def err(s):
+    """Print error message."""
+    print("\x1b[0;31mError\x1b[m " + s, file=sys.stderr)
+
+
+def warn(s):
+    """Print warning message."""
+    print("\x1b[0;33mWarn\x1b[m " + s, file=sys.stderr)
+
+
+def info(s):
+    """Print info message."""
+    print("\x1b[0;32mInfo\x1b[m " + s, file=sys.stderr)
+
+
 try:
     # package python-pyxdg on Arch
     from xdg.BaseDirectory import xdg_config_dirs
 except ModuleNotFoundError:
-    print("xdg module not found, defaulting to $HOME/.config", file=sys.stderr)
+    warn("xdg module not found, defaulting to $HOME/.config")
     import os
     home = os.getenv("HOME")
     xdg_config_dirs = [os.path.join(home, ".config")]
@@ -20,8 +39,7 @@ try:
     import yaml
     can_load_configuration = True
 except ModuleNotFoundError:
-    print("yaml module not found, configuration will NOT be loaded",
-          file=sys.stderr)
+    warn("yaml module not found, configuration will NOT be loaded")
 
 
 configuration = {
@@ -31,6 +49,7 @@ configuration = {
 
 
 def popen(str):
+    """Exec str, and return its stdout."""
     p = subprocess.Popen(str.split(" "),
                          universal_newlines=True,
                          stdout=subprocess.PIPE)
@@ -42,15 +61,24 @@ def popen(str):
 
 
 def gitconf(field):
+    """Get git config field, or die."""
     return popen("git config " + field)
 
 
 def remote_url(remote_name):
+    """Get url for git remote by name."""
     # return gitconf("remote.{}.url".format(remote_name))
     return popen(f'git remote get-url {remote_name}').strip()
 
 
 def to_http(url):
+    """
+    Convert url into matching HTTP url.
+
+    Uses configuration['patterns'] to check for special cases,
+    otherwise anything starting with http is returned verbatim, and
+    git@ is replaced with https://.
+    """
     for pattern in configuration['patterns']:
         if match := re.match(pattern['i'], url):
             rx = re.compile('[$]([0-9]+)')
@@ -74,28 +102,33 @@ def to_http(url):
 
 
 def xdg_open(item):
+    """Run xdg-open on argument."""
     subprocess.run(["xdg-open", item])
 
 
-def err(s):
-    print("\x1b[0;31mError\x1b[m " + s)
-
-
-def warn(s):
-    print("\x1b[0;33mWarn\x1b[m " + s)
-
-
-def info(s):
-    print("\x1b[0;32mInfo\x1b[m " + s)
-
-
 def open_remote(remote):
+    """Open url for the named remote."""
     url = to_http(remote_url(remote))
     xdg_open(url)
     info(f'opening {url}')
 
 
+def load_configuration():
+    """Load configuration file, updates `configuration`."""
+    global configuration
+    # TODO possibly add ~/.config/git/open.yaml to list
+    for dir in xdg_config_dirs:
+        try:
+            with open(os.path.join(dir, 'git-open.yaml')) as f:
+                conf = yaml.unsafe_load(f)
+                configuration |= conf
+                break
+        except FileNotFoundError:
+            pass
+
+
 def main(args):
+    """Entry point, args should come from ArgumentParser.parse_args."""
     out = popen("git remote")
     remotes = out.strip().split("\n")
 
@@ -127,19 +160,6 @@ def main(args):
         err("All remotes failed")
 
 
-def load_configuration():
-    global configuration
-    # TODO possibly add ~/.config/git/open.yaml to list
-    for dir in xdg_config_dirs:
-        try:
-            with open(os.path.join(dir, 'git-open.yaml')) as f:
-                conf = yaml.unsafe_load(f)
-                configuration |= conf
-                break
-        except FileNotFoundError:
-            pass
-
-
 if __name__ == "__main__":
     # Note that argparse gives `--help' and `-h', but git "eats"
     # `--help'. `-h' does however work.