diff --git a/dotdrop/cfg_yaml.py b/dotdrop/cfg_yaml.py
index bab7896..3b8b868 100644
--- a/dotdrop/cfg_yaml.py
+++ b/dotdrop/cfg_yaml.py
@@ -18,6 +18,8 @@ the upper layer:
 Additionally a few methods are exported.
 """
 
+# pylint: disable=C0302
+
 import os
 import glob
 import io
@@ -31,7 +33,7 @@ from dotdrop.settings import Settings
 from dotdrop.logger import Logger
 from dotdrop.templategen import Templategen
 from dotdrop.linktypes import LinkTypes
-from dotdrop.utils import shell, uniq_list
+from dotdrop.utils import shellrun, uniq_list
 from dotdrop.exceptions import YamlException, UndefinedException
 
 
@@ -96,7 +98,7 @@ class CfgYaml:
     allowed_link_val = [lnk_nolink, lnk_link, lnk_children]
     top_entries = [key_dotfiles, key_settings, key_profiles]
 
-    def __init__(self, path, profile=None, addprofiles=[], debug=False):
+    def __init__(self, path, profile=None, addprofiles=None, debug=False):
         """
         config parser
         @path: config file path
@@ -115,7 +117,7 @@ class CfgYaml:
         # profile variables
         self._profilevarskeys = []
         # included profiles
-        self._inc_profiles = addprofiles
+        self._inc_profiles = addprofiles or []
 
         # init the dictionaries
         self.settings = {}
@@ -180,11 +182,11 @@ class CfgYaml:
 
         # include the profile's variables/dynvariables last
         # as it overwrites existing ones
-        self._inc_profiles, pv, pvd = self._get_profile_included_vars()
-        self._add_variables(pv, prio=True)
-        self._add_variables(pvd, shell=True, prio=True)
-        self._profilevarskeys.extend(pv.keys())
-        self._profilevarskeys.extend(pvd.keys())
+        self._inc_profiles, pvar, pdvar = self._get_profile_included_vars()
+        self._add_variables(pvar, prio=True)
+        self._add_variables(pdvar, shell=True, prio=True)
+        self._profilevarskeys.extend(pvar.keys())
+        self._profilevarskeys.extend(pdvar.keys())
 
         # template variables
         self.variables = self._template_dict(self.variables)
@@ -232,11 +234,11 @@ class CfgYaml:
         self._resolve_profile_includes()
 
         # add the current profile variables
-        _, pv, pvd = self._get_profile_included_vars()
-        self._add_variables(pv, prio=False)
-        self._add_variables(pvd, shell=True, prio=False)
-        self._profilevarskeys.extend(pv.keys())
-        self._profilevarskeys.extend(pvd.keys())
+        _, pvar, pdvar = self._get_profile_included_vars()
+        self._add_variables(pvar, prio=False)
+        self._add_variables(pdvar, shell=True, prio=False)
+        self._profilevarskeys.extend(pvar.keys())
+        self._profilevarskeys.extend(pdvar.keys())
 
         # resolve variables
         self._clear_profile_vars(newvars)
@@ -322,21 +324,21 @@ class CfgYaml:
         """update an existing dotfile"""
         if key not in self.dotfiles.keys():
             return False
-        df = self._yaml_dict[self.key_dotfiles][key]
+        dotfile = self._yaml_dict[self.key_dotfiles][key]
         old = None
-        if self.key_dotfile_chmod in df:
-            old = df[self.key_dotfile_chmod]
+        if self.key_dotfile_chmod in dotfile:
+            old = dotfile[self.key_dotfile_chmod]
         if old == chmod:
             return False
         if self._debug:
             self._dbg('update dotfile: {}'.format(key))
             self._dbg('old chmod value: {}'.format(old))
             self._dbg('new chmod value: {}'.format(chmod))
-        df = self._yaml_dict[self.key_dotfiles][key]
+        dotfile = self._yaml_dict[self.key_dotfiles][key]
         if not chmod:
-            del df[self.key_dotfile_chmod]
+            del dotfile[self.key_dotfile_chmod]
         else:
-            df[self.key_dotfile_chmod] = str(format(chmod, 'o'))
+            dotfile[self.key_dotfile_chmod] = str(format(chmod, 'o'))
         self._dirty = True
         return True
 
@@ -426,11 +428,12 @@ class CfgYaml:
         if self._debug:
             self._dbg('saving to {}'.format(self._path))
         try:
-            with open(self._path, 'w') as f:
-                self._yaml_dump(content, f)
-        except Exception as e:
-            self._log.err(e)
-            raise YamlException('error saving config: {}'.format(self._path))
+            with open(self._path, 'w') as file:
+                self._yaml_dump(content, file)
+        except Exception as exc:
+            self._log.err(exc)
+            err = 'error saving config: {}'.format(self._path)
+            raise YamlException(err) from exc
 
         if self._dirty_deprecated:
             warn = 'your config contained deprecated entries'
@@ -587,11 +590,11 @@ class CfgYaml:
             self.settings[self.key_import_variables] = new
 
         # profile's import
-        for k, v in self.profiles.items():
-            entries = v.get(self.key_import_profile_dfs, [])
+        for _, val in self.profiles.items():
+            entries = val.get(self.key_import_profile_dfs, [])
             new = self._template_list(entries)
             if new:
-                v[self.key_import_profile_dfs] = new
+                val[self.key_import_profile_dfs] = new
 
     def _norm_actions(self, actions):
         """
@@ -601,12 +604,12 @@ class CfgYaml:
         if not actions:
             return actions
         new = {}
-        for k, v in actions.items():
-            if k == self.action_pre or k == self.action_post:
-                for key, action in v.items():
+        for k, val in actions.items():
+            if k in (self.action_pre, self.action_post):
+                for key, action in val.items():
                     new[key] = (k, action)
             else:
-                new[k] = (self.action_post, v)
+                new[k] = (self.action_post, val)
         return new
 
     def _norm_profiles(self, profiles):
@@ -614,14 +617,14 @@ class CfgYaml:
         if not profiles:
             return profiles
         new = {}
-        for k, v in profiles.items():
-            if not v:
+        for k, val in profiles.items():
+            if not val:
                 # no dotfiles
                 continue
             # add dotfiles entry if not present
-            if self.key_profile_dotfiles not in v:
-                v[self.key_profile_dotfiles] = []
-            new[k] = v
+            if self.key_profile_dotfiles not in val:
+                val[self.key_profile_dotfiles] = []
+            new[k] = val
         return new
 
     def _norm_dotfiles(self, dotfiles):
@@ -629,55 +632,56 @@ class CfgYaml:
         if not dotfiles:
             return dotfiles
         new = {}
-        for k, v in dotfiles.items():
+        for k, val in dotfiles.items():
             # add 'src' as key' if not present
-            if self.key_dotfile_src not in v:
-                v[self.key_dotfile_src] = k
-                new[k] = v
+            if self.key_dotfile_src not in val:
+                val[self.key_dotfile_src] = k
+                new[k] = val
             else:
-                new[k] = v
+                new[k] = val
             # fix deprecated trans key
-            if self.old_key_trans_r in v:
+            if self.old_key_trans_r in val:
                 msg = '\"trans\" is deprecated, please use \"trans_read\"'
                 self._log.warn(msg)
-                v[self.key_trans_r] = v[self.old_key_trans_r]
-                del v[self.old_key_trans_r]
-                new[k] = v
-            if self.key_dotfile_link not in v:
+                val[self.key_trans_r] = val[self.old_key_trans_r]
+                del val[self.old_key_trans_r]
+                new[k] = val
+            if self.key_dotfile_link not in val:
                 # apply link value if undefined
-                val = self.settings[self.key_settings_link_dotfile_default]
-                v[self.key_dotfile_link] = val
+                value = self.settings[self.key_settings_link_dotfile_default]
+                val[self.key_dotfile_link] = value
             # apply noempty if undefined
-            if self.key_dotfile_noempty not in v:
-                val = self.settings.get(self.key_settings_noempty, False)
-                v[self.key_dotfile_noempty] = val
+            if self.key_dotfile_noempty not in val:
+                value = self.settings.get(self.key_settings_noempty, False)
+                val[self.key_dotfile_noempty] = value
             # apply template if undefined
-            if self.key_dotfile_template not in v:
-                val = self.settings.get(self.key_settings_template, True)
-                v[self.key_dotfile_template] = val
+            if self.key_dotfile_template not in val:
+                value = self.settings.get(self.key_settings_template, True)
+                val[self.key_dotfile_template] = value
             # validate value of chmod if defined
-            if self.key_dotfile_chmod in v:
-                val = str(v[self.key_dotfile_chmod])
-                if len(val) < 3:
-                    err = 'bad format for chmod: {}'.format(val)
+            if self.key_dotfile_chmod in val:
+                value = str(val[self.key_dotfile_chmod])
+                if len(value) < 3:
+                    err = 'bad format for chmod: {}'.format(value)
                     self._log.err(err)
                     raise YamlException('config content error: {}'.format(err))
                 try:
-                    int(val)
-                except Exception:
-                    err = 'bad format for chmod: {}'.format(val)
+                    int(value)
+                except Exception as exc:
+                    err = 'bad format for chmod: {}'.format(value)
                     self._log.err(err)
-                    raise YamlException('config content error: {}'.format(err))
+                    err = 'config content error: {}'.format(err)
+                    raise YamlException(err) from exc
                 # normalize chmod value
-                for x in list(val):
-                    y = int(x)
-                    if y < 0 or y > 7:
-                        err = 'bad format for chmod: {}'.format(val)
+                for chmodv in list(value):
+                    chmodint = int(chmodv)
+                    if chmodint < 0 or chmodint > 7:
+                        err = 'bad format for chmod: {}'.format(value)
                         self._log.err(err)
                         raise YamlException(
                             'config content error: {}'.format(err)
                         )
-                v[self.key_dotfile_chmod] = int(val, 8)
+                val[self.key_dotfile_chmod] = int(value, 8)
 
         return new
 
@@ -719,13 +723,13 @@ class CfgYaml:
         if profile:
             variables['profile'] = profile
         # add some more variables
-        p = self.settings.get(self.key_settings_dotpath)
-        p = self._norm_path(p)
-        variables['_dotdrop_dotpath'] = p
+        path = self.settings.get(self.key_settings_dotpath)
+        path = self._norm_path(path)
+        variables['_dotdrop_dotpath'] = path
         variables['_dotdrop_cfgpath'] = self._norm_path(self._path)
-        p = self.settings.get(self.key_settings_workdir)
-        p = self._norm_path(p)
-        variables['_dotdrop_workdir'] = p
+        path = self.settings.get(self.key_settings_workdir)
+        path = self._norm_path(path)
+        variables['_dotdrop_workdir'] = path
         return variables
 
     def _get_profile_included_item(self, keyitem):
@@ -765,18 +769,18 @@ class CfgYaml:
     def _resolve_profile_all(self):
         """resolve some other parts of the config"""
         # profile -> ALL
-        for k, v in self.profiles.items():
-            dfs = v.get(self.key_profile_dotfiles, None)
+        for k, val in self.profiles.items():
+            dfs = val.get(self.key_profile_dotfiles, None)
             if not dfs:
                 continue
             if self.key_all in dfs:
                 if self._debug:
                     self._dbg('add ALL to profile \"{}\"'.format(k))
-                v[self.key_profile_dotfiles] = self.dotfiles.keys()
+                val[self.key_profile_dotfiles] = self.dotfiles.keys()
 
     def _resolve_profile_includes(self):
         """resolve profile(s) including other profiles"""
-        for k, v in self.profiles.items():
+        for k, _ in self.profiles.items():
             self._rec_resolve_profile_include(k)
 
     def _rec_resolve_profile_include(self, profile):
@@ -860,7 +864,7 @@ class CfgYaml:
         """import external variables from paths"""
         paths = self.settings.get(self.key_import_variables, None)
         if not paths:
-            return
+            return None
         paths = self._resolve_paths(paths)
         newvars = {}
         for path in paths:
@@ -899,18 +903,18 @@ class CfgYaml:
 
     def _import_profiles_dotfiles(self):
         """import profile dotfiles"""
-        for k, v in self.profiles.items():
-            imp = v.get(self.key_import_profile_dfs, None)
+        for k, val in self.profiles.items():
+            imp = val.get(self.key_import_profile_dfs, None)
             if not imp:
                 continue
             if self._debug:
                 self._dbg('import dotfiles for profile {}'.format(k))
             paths = self._resolve_paths(imp)
             for path in paths:
-                current = v.get(self.key_dotfiles, [])
+                current = val.get(self.key_dotfiles, [])
                 new = self._import_sub(path, self.key_dotfiles,
                                        mandatory=False)
-                v[self.key_dotfiles] = new + current
+                val[self.key_dotfiles] = new + current
 
     def _import_config(self, path):
         """import config from path"""
@@ -999,7 +1003,6 @@ class CfgYaml:
             return
         self._fix_deprecated_link_by_default(yamldict)
         self._fix_deprecated_dotfile_link(yamldict)
-        return yamldict
 
     def _fix_deprecated_link_by_default(self, yamldict):
         """fix deprecated link_by_default"""
@@ -1028,9 +1031,9 @@ class CfgYaml:
             return
         if not yamldict[self.key_dotfiles]:
             return
-        for k, dotfile in yamldict[self.key_dotfiles].items():
+        for _, dotfile in yamldict[self.key_dotfiles].items():
             if self.key_dotfile_link in dotfile and \
-                    type(dotfile[self.key_dotfile_link]) is bool:
+                    isinstance(dotfile[self.key_dotfile_link], bool):
                 # patch link: <bool>
                 cur = dotfile[self.key_dotfile_link]
                 new = self.lnk_nolink
@@ -1042,7 +1045,7 @@ class CfgYaml:
                 self._log.warn('deprecated \"link\" value')
 
             elif old_key in dotfile and \
-                    type(dotfile[old_key]) is bool:
+                    isinstance(dotfile[old_key], bool):
                 # patch link_children: <bool>
                 cur = dotfile[old_key]
                 new = self.lnk_nolink
@@ -1076,16 +1079,17 @@ class CfgYaml:
         if self._debug:
             self._dbg('----------start:{}----------'.format(path))
             cfg = '\n'
-            with open(path, 'r') as f:
-                for line in f:
+            with open(path, 'r') as file:
+                for line in file:
                     cfg += line
             self._dbg(cfg.rstrip())
             self._dbg('----------end:{}----------'.format(path))
         try:
             content = self._yaml_load(path)
-        except Exception as e:
-            self._log.err(e)
-            raise YamlException('config yaml error: {}'.format(path))
+        except Exception as exc:
+            self._log.err(exc)
+            err = 'config yaml error: {}'.format(path)
+            raise YamlException(err) from exc
 
         return content
 
@@ -1095,9 +1099,9 @@ class CfgYaml:
             return
 
         # check top entries
-        for e in self.top_entries:
-            if e not in yamldict:
-                err = 'no {} entry found'.format(e)
+        for entry in self.top_entries:
+            if entry not in yamldict:
+                err = 'no {} entry found'.format(entry)
                 self._log.err(err)
                 raise YamlException('config format error: {}'.format(err))
 
@@ -1117,21 +1121,23 @@ class CfgYaml:
             self._log.err(err)
             raise YamlException('config content error: {}'.format(err))
 
-    def _yaml_load(self, path):
+    @classmethod
+    def _yaml_load(cls, path):
         """load from yaml"""
-        with open(path, 'r') as f:
-            y = yaml()
-            y.typ = 'rt'
-            content = y.load(f)
+        with open(path, 'r') as file:
+            data = yaml()
+            data.typ = 'rt'
+            content = data.load(file)
         return content
 
-    def _yaml_dump(self, content, where):
+    @classmethod
+    def _yaml_dump(cls, content, where):
         """dump to yaml"""
-        y = yaml()
-        y.default_flow_style = False
-        y.indent = 2
-        y.typ = 'rt'
-        y.dump(content, where)
+        data = yaml()
+        data.default_flow_style = False
+        data.indent = 2
+        data.typ = 'rt'
+        data.dump(content, where)
 
     ########################################################
     # templating
@@ -1156,9 +1162,9 @@ class CfgYaml:
             val = item
             while Templategen.var_is_template(val):
                 val = self._tmpl.generate_string(val)
-        except UndefinedException as e:
+        except UndefinedException as exc:
             if exc_if_fail:
-                raise e
+                raise exc
         return val
 
     def _template_list(self, entries):
@@ -1459,7 +1465,7 @@ class CfgYaml:
             keys = dic.keys()
         for k in keys:
             val = dic[k]
-            ret, out = shell(val, debug=self._debug)
+            ret, out = shellrun(val, debug=self._debug)
             if not ret:
                 err = 'var \"{}: {}\" failed: {}'.format(k, val, out)
                 self._log.err(err)
diff --git a/dotdrop/dotdrop.py b/dotdrop/dotdrop.py
index ce5fafd..d6ef02a 100644
--- a/dotdrop/dotdrop.py
+++ b/dotdrop/dotdrop.py
@@ -333,6 +333,7 @@ def cmd_install(opts):
         # check result
         for fut in futures.as_completed(wait_for):
             tmpret, key, err = fut.result()
+            # check result
             if tmpret:
                 installed.append(key)
             elif err:
diff --git a/dotdrop/installer.py b/dotdrop/installer.py
index d99a0b6..f834a4e 100644
--- a/dotdrop/installer.py
+++ b/dotdrop/installer.py
@@ -356,7 +356,9 @@ class Installer:
         - False, 'aborted'    : user aborted
         """
         overwrite = not self.safe
+
         if os.path.lexists(dst):
+            # symlink exists
             if os.path.realpath(dst) == os.path.realpath(src):
                 msg = 'ignoring "{}", link already exists'.format(dst)
                 self.log.dbg(msg)
@@ -369,22 +371,29 @@ class Installer:
             msg = 'Remove "{}" for link creation?'.format(dst)
             if self.safe and not self.log.ask(msg):
                 return False, 'aborted'
+
+            # remove symlink
             overwrite = True
             try:
                 utils.removepath(dst)
             except OSError as exc:
                 err = 'something went wrong with {}: {}'.format(src, exc)
                 return False, err
+
         if self.dry:
             self.log.dry('would link {} to {}'.format(dst, src))
             return True, None
+
         base = os.path.dirname(dst)
         if not self._create_dirs(base):
             err = 'error creating directory for {}'.format(dst)
             return False, err
+
+        # execute pre-actions
         ret, err = self._exec_pre_actions(actionexec)
         if not ret:
             return False, err
+
         # re-check in case action created the file
         if os.path.lexists(dst):
             msg = 'Remove "{}" for link creation?'.format(dst)
@@ -395,6 +404,8 @@ class Installer:
             except OSError as exc:
                 err = 'something went wrong with {}: {}'.format(src, exc)
                 return False, err
+
+        # create symlink
         os.symlink(src, dst)
         if not self.comparing:
             self.log.sub('linked {} to {}'.format(dst, src))
@@ -418,20 +429,17 @@ class Installer:
         self.log.dbg('is_template: {}'.format(is_template))
         self.log.dbg('no empty: {}'.format(noempty))
 
+        # ignore file
+        if utils.must_ignore([src, dst], ignore, debug=self.debug):
+            self.log.dbg('ignoring install of {} to {}'.format(src, dst))
+            return False, None
+
         # check no loop
         if utils.samefile(src, dst):
             err = 'dotfile points to itself: {}'.format(dst)
             return False, err
 
-        if utils.must_ignore([src, dst], ignore, debug=self.debug):
-            self.log.dbg('ignoring install of {} to {}'.format(src, dst))
-            return False, None
-
-        if utils.samefile(src, dst):
-            # loop
-            err = 'dotfile points to itself: {}'.format(dst)
-            return False, err
-
+        # check source file exists
         if not os.path.exists(src):
             err = 'source dotfile does not exist: {}'.format(src)
             return False, err
@@ -499,9 +507,9 @@ class Installer:
                                            is_template=is_template)
                 if not res and err:
                     # error occured
-                    ret = res, err
-                    break
-                elif res:
+                    return res, err
+
+                if res:
                     # something got installed
                     ret = True, None
             else:
@@ -514,9 +522,9 @@ class Installer:
                                           is_template=is_template)
                 if not res and err:
                     # error occured
-                    ret = res, err
-                    break
-                elif res:
+                    return res, err
+
+                if res:
                     # something got installed
                     ret = True, None
         return ret
@@ -563,6 +571,7 @@ class Installer:
             return True, None
 
         if os.path.lexists(dst):
+            # file/symlink exists
             try:
                 os.stat(dst)
             except OSError as exc:
@@ -575,6 +584,7 @@ class Installer:
                 if not self._is_different(src, dst, content=content):
                     self.log.dbg('{} is the same'.format(dst))
                     return False, None
+
             if self.safe:
                 self.log.dbg('change detected for {}'.format(dst))
                 if self.showdiff:
@@ -585,8 +595,8 @@ class Installer:
                     return False, 'aborted'
                 overwrite = True
 
-        if self.backup and os.path.lexists(dst):
-            self._backup(dst)
+            if self.backup:
+                self._backup(dst)
 
         # create hierarchy
         base = os.path.dirname(dst)
diff --git a/dotdrop/options.py b/dotdrop/options.py
index 7d35da5..276f0e9 100644
--- a/dotdrop/options.py
+++ b/dotdrop/options.py
@@ -5,6 +5,7 @@ Copyright (c) 2017, deadc0de6
 stores all options to use across dotdrop
 """
 
+# attribute-defined-outside-init
 # pylint: disable=W0201
 
 import os
@@ -164,7 +165,27 @@ class Options(AttrMonitor):
         # start monitoring for bad attribute
         self._set_attr_err = True
 
-# pylint: disable=R0911
+    @classmethod
+    def _get_config_from_fs(cls):
+        """get config from filesystem"""
+        # look in ~/.config/dotdrop
+        cfg = os.path.expanduser(HOMECFG)
+        path = os.path.join(cfg, CONFIG)
+        if os.path.exists(path):
+            return path
+
+        # look in /etc/xdg/dotdrop
+        path = os.path.join(ETCXDGCFG, CONFIG)
+        if os.path.exists(path):
+            return path
+
+        # look in /etc/dotdrop
+        path = os.path.join(ETCCFG, CONFIG)
+        if os.path.exists(path):
+            return path
+
+        return ''
+
     def _get_config_path(self):
         """get the config path"""
         # cli provided
@@ -186,24 +207,7 @@ class Options(AttrMonitor):
             if os.path.exists(path):
                 return path
 
-        # look in ~/.config/dotdrop
-        cfg = os.path.expanduser(HOMECFG)
-        path = os.path.join(cfg, CONFIG)
-        if os.path.exists(path):
-            return path
-
-        # look in /etc/xdg/dotdrop
-        path = os.path.join(ETCXDGCFG, CONFIG)
-        if os.path.exists(path):
-            return path
-
-        # look in /etc/dotdrop
-        path = os.path.join(ETCCFG, CONFIG)
-        if os.path.exists(path):
-            return path
-
-        return ''
-# pylint: enable=R0911
+        return self._get_config_from_fs()
 
     def _header(self):
         """display the header"""
diff --git a/dotdrop/utils.py b/dotdrop/utils.py
index bfe959e..c3dcf1c 100644
--- a/dotdrop/utils.py
+++ b/dotdrop/utils.py
@@ -56,7 +56,7 @@ def write_to_tmpfile(content):
     return path
 
 
-def shell(cmd, debug=False):
+def shellrun(cmd, debug=False):
     """
     run a command in the shell (expects a string)
     returns True|False, output
@@ -256,8 +256,7 @@ def uniq_list(a_list):
 def patch_ignores(ignores, prefix, debug=False):
     """allow relative ignore pattern"""
     new = []
-    if debug:
-        LOG.dbg('ignores before patching: {}'.format(ignores), force=True)
+    LOG.dbg('ignores before patching: {}'.format(ignores), force=debug)
     for ignore in ignores:
         negative = ignore.startswith('!')
         if negative:
@@ -284,8 +283,7 @@ def patch_ignores(ignores, prefix, debug=False):
             new.append('!' + path)
         else:
             new.append(path)
-    if debug:
-        LOG.dbg('ignores after patching: {}'.format(new), force=True)
+    LOG.dbg('ignores after patching: {}'.format(new), force=debug)
     return new
 
 
@@ -305,8 +303,12 @@ def get_module_from_path(path):
     if not path or not os.path.exists(path):
         return None
     module_name = os.path.basename(path).rstrip('.py')
-    loader = importlib.machinery.SourceFileLoader(module_name, path)
-    mod = loader.load_module()
+    # allow any type of files
+    importlib.machinery.SOURCE_SUFFIXES.append('')
+    # import module
+    spec = importlib.util.spec_from_file_location(module_name, path)
+    mod = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(mod)
     return mod
 
 
diff --git a/scripts/change-link.py b/scripts/change-link.py
index f61a419..ec75312 100755
--- a/scripts/change-link.py
+++ b/scripts/change-link.py
@@ -10,8 +10,9 @@ usage example:
     ./change-link.py --true ../config.yaml --ignore f_vimrc --ignore f_xinitrc
 """
 
-from docopt import docopt
 import os
+import io
+from docopt import docopt
 from ruamel.yaml import YAML as yaml
 
 USAGE = """
@@ -26,11 +27,12 @@ Options:
 
 """
 
-key = 'dotfiles'
-entry = 'link'
+KEY = 'dotfiles'
+ENTRY = 'link'
 
 
 def main():
+    """entry point"""
     args = docopt(USAGE)
     path = os.path.expanduser(args['<config.yaml>'])
     if args['--true']:
@@ -40,19 +42,19 @@ def main():
 
     ignores = args['--ignore']
 
-    with open(path, 'r') as f:
-        content = yaml(typ='safe').load(f)
-    for k, v in content[key].items():
+    with open(path, 'r') as file:
+        content = yaml(typ='safe').load(file)
+    for k, val in content[KEY].items():
         if k in ignores:
             continue
-        v[entry] = value
+        val[ENTRY] = value
 
     output = io.StringIO()
-    y = yaml()
-    y.default_flow_style = False
-    y.indent = 2
-    y.typ = 'rt'
-    y.dump(content, output)
+    data = yaml()
+    data.default_flow_style = False
+    data.indent = 2
+    data.typ = 'rt'
+    data.dump(content, output)
     print(output)