Initial :config-write-py implementation

qutebrowser/config/config.py

@@ -223,6 +223,11 @@ class Config(QObject):
         self._mutables = {}
         self._yaml = yaml_config
 
+    def __iter__(self):
+        """Iterate over Option, value tuples."""
+        for name, value in sorted(self._values.items()):
+            yield (self.get_opt(name), value)
+
     def init_save_manager(self, save_manager):
         """Make sure the config gets saved properly.
 
@@ -365,10 +370,9 @@ class Config(QObject):
             The changed config part as string.
         """
         lines = []
-        for optname, value in sorted(self._values.items()):
-            opt = self.get_opt(optname)
+        for opt, value in self:
             str_value = opt.typ.to_str(value)
-            lines.append('{} = {}'.format(optname, str_value))
+            lines.append('{} = {}'.format(opt.name, str_value))
         if not lines:
             lines = ['<Default configuration>']
         return '\n'.join(lines)

qutebrowser/config/configcommands.py

@@ -27,7 +27,7 @@ from PyQt5.QtCore import QUrl
 from qutebrowser.commands import cmdexc, cmdutils
 from qutebrowser.completion.models import configmodel
 from qutebrowser.utils import objreg, utils, message, standarddir
-from qutebrowser.config import configtypes, configexc, configfiles
+from qutebrowser.config import configtypes, configexc, configfiles, configdata
 from qutebrowser.misc import editor
 
 
@@ -246,3 +246,31 @@ class ConfigCommands:
 
         filename = os.path.join(standarddir.config(), 'config.py')
         ed.edit_file(filename)
+
+    @cmdutils.register(instance='config-commands')
+    def config_write_py(self, filename=None, force=False, defaults=False):
+        """Write the current configuration to a config.py file.
+
+        Args:
+            filename: The file to write to, or None for the default config.py.
+            force: Force overwriting existing files.
+            defaults: Write the defaults instead of values configured via :set.
+        """
+        if filename is None:
+            filename = os.path.join(standarddir.config(), 'config.py')
+        else:
+            filename = os.path.expanduser(filename)
+
+        if os.path.exists(filename) and not force:
+            raise cmdexc.CommandError("{} already exists - use --force to "
+                                      "overwrite!".format(filename))
+
+        if defaults:
+            options = [(opt, opt.default)
+                       for _name, opt in sorted(configdata.DATA.items())]
+            bindings = dict(configdata.DATA['bindings.default'].default)
+        else:
+            options = list(self._config)
+            bindings = dict(self._config.get_obj('bindings.commands'))
+
+        configfiles.write_config_py(filename, options, bindings)

qutebrowser/config/configfiles.py

@@ -245,6 +245,28 @@ class ConfigAPI:
             self._keyconfig.unbind(key, mode=mode)
 
 
+def write_config_py(filename, options, bindings):
+    """Write a config.py file from given values."""
+    with open(filename, 'w', encoding='utf-8') as f:
+        for opt, value in options:
+            if opt.name in ['bindings.commands', 'bindings.default']:
+                continue
+            for line in textwrap.wrap(opt.description):
+                f.write('# {}\n'.format(line))
+            f.write('c.{} = {!r}\n\n'.format(opt.name, value))
+
+        normal_bindings = bindings.pop('normal', {})
+        f.write('# Bindings for normal mode\n')
+        for key, command in sorted(normal_bindings.items()):
+            f.write('config.bind({!r}, {!r})\n'.format(key, command))
+
+        for mode, mode_bindings in sorted(bindings.items()):
+            f.write('\n# Bindings for {} mode\n'.format(mode))
+            for key, command in sorted(mode_bindings.items()):
+                f.write('config.bind({!r}, {!r}, mode={!r})\n'.format(
+                    key, command, mode))
+
+
 def read_config_py(filename, raising=False):
     """Read a config.py file.