Standardize the use of single/double quotes

Single qoutes should be used for symbol-like/identifier strings
and double quotes for everything else.
I know this is quite vague but it suits me.
Inspired by http://stackoverflow.com/a/56190

Author: xxdavid

src/analyses.py

@@ -39,7 +39,7 @@ def __init__(self):
 
     @property
     def name(self):
-        return "word_frequency"
+        return 'word_frequency'
 
     def analyze_commit(self, author, repo, lines, message):
         words = message.split(" ")
@@ -70,7 +70,7 @@ def state(self, value):
 class FirstWordFrequencyAnalysis(WordFrequencyAnalysis):
     @property
     def name(self):
-        return "first_word_frequency"
+        return 'first_word_frequency'
 
     def analyze_commit(self, author, repo, lines, message):
         words = message.split(" ")
@@ -85,10 +85,10 @@ def analyze_commit(self, author, repo, lines, message):
 class VerbFormAnalysis(Analysis):
     def __init__(self):
         self.forms = [
-            "imperative",
-            "gerund",
-            "third_person",
-            "past_tense"
+            'imperative',
+            'gerund',
+            'third_person',
+            'past_tense'
         ]
 
         self.lists = {}
@@ -107,7 +107,7 @@ def __init__(self):
 
     @property
     def name(self):
-        return "verb_form"
+        return 'verb_form'
 
     def analyze_commit(self, author, repo, lines, message):
         word = message.split(" ")[0].lower()
@@ -162,7 +162,7 @@ def __init__(self):
 
     @property
     def name(self):
-        return "message_length"
+        return 'message_length'
 
     def analyze_commit(self, author, repo, lines, message):
         length = len(message)
@@ -182,7 +182,7 @@ def __init__(self):
 
     @property
     def name(self):
-        return "message_line_count"
+        return 'message_line_count'
 
     def analyze_commit(self, author, repo, lines, message):
         if lines in self.lineCounts:
@@ -211,7 +211,7 @@ def __init__(self):
 
     @property
     def name(self):
-        return "binary"
+        return 'binary'
 
     def analyze_commit(self, author, repo, lines, message):
         if len(message) > 0:

src/generate_conjugations.py

@@ -9,7 +9,7 @@
 
 forms = ['imperative', 'third_person', 'gerund', 'past_tense']
 for form in forms:
-    file = open_file_dir_safe(f"{Directories.processed_data}/{form}.txt", "w")
+    file = open_file_dir_safe(f"{Directories.processed_data}/{form}.txt", 'w')
     with file:
         for word in infinitives:
             method = getattr(generator, form)

src/plotters.py

@@ -102,7 +102,7 @@ def init_plot(self):
 class WordFrequencyPlotter(BarPlotter):
     @property
     def name(self):
-        return "word_frequency"
+        return 'word_frequency'
 
     @property
     def title(self):
@@ -131,7 +131,7 @@ def compute_values(self):
 class FirstWordFrequencyPlotter(WordFrequencyPlotter):
     @property
     def name(self):
-        return "first_word_frequency"
+        return 'first_word_frequency'
 
     @property
     def title(self):
@@ -141,11 +141,11 @@ def title(self):
 class VerbFormOverviewPlotter(BarPlotter):
     @property
     def name(self):
-        return "verb_form_overview"
+        return 'verb_form_overview'
 
     @property
     def input_file_name(self):
-        return "verb_form"
+        return 'verb_form'
 
     @property
     def title(self):
@@ -176,11 +176,11 @@ def form(self):
 
     @property
     def name(self):
-        return f"verb_form_{self.form}_frequency"
+        return f'verb_form_{self.form}_frequency'
 
     @property
     def input_file_name(self):
-        return "verb_form"
+        return 'verb_form'
 
     @property
     def title(self):
@@ -202,31 +202,31 @@ def compute_values(self):
 class ImperativePlotter(VerbFormWordsPlotter):
     @property
     def form(self):
-        return "imperative"
+        return 'imperative'
 
 
 class GerundWordsPlotter(VerbFormWordsPlotter):
     @property
     def form(self):
-        return "gerund"
+        return 'gerund'
 
 
 class ThirdPersonWordsPlotter(VerbFormWordsPlotter):
     @property
     def form(self):
-        return "third_person"
+        return 'third_person'
 
 
 class PastTenseWordsPlotter(VerbFormWordsPlotter):
     @property
     def form(self):
-        return "past_tense"
+        return 'past_tense'
 
 
 class MessageLengthPlotter(LinePlotter):
     @property
     def name(self):
-        return "message_length"
+        return 'message_length'
 
     @property
     def title(self):
@@ -249,7 +249,7 @@ def compute_values(self):
 class MessageLinesPlotter(LinePlotter):
     @property
     def name(self):
-        return "message_line_count"
+        return 'message_line_count'
 
     @property
     def title(self):
@@ -272,7 +272,7 @@ def compute_values(self):
 class BinaryAnalysesPlotter(BarPlotter):
     @property
     def name(self):
-        return "binary"
+        return 'binary'
 
     @property
     def title(self):
@@ -290,10 +290,10 @@ def compute_values(self):
         total_count = self.data['total']
 
         labels = {
-            'capital_letter': 'Capital letter',
-            'full_stop': 'Full stop',
-            'capslock': 'CAPSLOCK ON',
-            'non_ascii_chars': 'Contains non-ASCII chars'
+            'capital_letter': "Capital letter",
+            'full_stop': "Full stop",
+            'capslock': "CAPSLOCK ON",
+            'non_ascii_chars': "Contains non-ASCII chars"
         }
 
         values = [

src/process_verbs.py

@@ -6,7 +6,7 @@
 
 input_file = open(f"{Directories.raw_data}/verbs.txt")
 output_file =\
-    open_file_dir_safe(f"{Directories.processed_data}/infinitive.txt", "w")
+    open_file_dir_safe(f"{Directories.processed_data}/infinitive.txt", 'w')
 
 with input_file, output_file:
     for line in input_file: