Flyweight Patterns

Author: MilovanTomasevic

src/1_patterns/3_StructuralPatterns/6_Flyweight/1_users.py

@@ -0,0 +1,49 @@
+import random
+import string
+import sys
+
+class User:
+    def __init__(self, name):
+        self.name = name
+
+class User2:
+    strings = []
+
+    def __init__(self, full_name):
+        def get_or_add(s):
+            if s in self.strings:
+                return self.strings.index(s)
+            else:
+                self.strings.append(s)
+                return len(self.strings)-1
+        self.names = [get_or_add(x) for x in full_name.split(' ')]
+
+    def __str__(self):
+        return ' '.join([self.strings[x] for x in self.names])
+
+def random_string():
+    chars = string.ascii_lowercase
+    return ''.join([random.choice(chars) for x in range(8)])
+
+
+if __name__ == '__main__':
+    users = []
+
+    first_names = [random_string() for x in range(100)]
+    last_names = [random_string() for x in range(100)]
+
+    for first in first_names:
+        for last in last_names:
+            users.append(User(f'{first} {last}'))
+
+    u2 = User2('Jim Jones')
+    u3 = User2('Frank Jones')
+    print(u2.names)
+    print(u3.names)
+    print(User2.strings)
+
+    users2 = []
+
+    for first in first_names:
+        for last in last_names:
+            users2.append(User2(f'{first} {last}'))

src/1_patterns/3_StructuralPatterns/6_Flyweight/2_text_formatting.py

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+class FormattedText:
+    def __init__(self, plain_text):
+        self.plain_text = plain_text
+        self.caps = [False] * len(plain_text)
+
+    def capitalize(self, start, end):
+        for i in range(start, end):
+            self.caps[i] = True
+
+    def __str__(self):
+        result = []
+        for i in range(len(self.plain_text)):
+            c = self.plain_text[i]
+            result.append(c.upper() if self.caps[i] else c)
+        return ''.join(result)
+
+
+class BetterFormattedText:
+    def __init__(self, plain_text):
+        self.plain_text = plain_text
+        self.formatting = []
+
+    class TextRange:
+        def __init__(self, start, end, capitalize=False, bold=False, italic=False):
+            self.end = end
+            self.bold = bold
+            self.capitalize = capitalize
+            self.italic = italic
+            self.start = start
+
+        def covers(self, position):
+            return self.start <= position <= self.end
+
+    def get_range(self, start, end):
+        range = self.TextRange(start, end)
+        self.formatting.append(range)
+        return range
+
+    def __str__(self):
+        result = []
+        for i in range(len(self.plain_text)):
+            c = self.plain_text[i]
+            for r in self.formatting:
+                if r.covers(i) and r.capitalize:
+                    c = c.upper()
+            result.append(c)
+        return ''.join(result)
+
+
+if __name__ == '__main__':
+    ft = FormattedText('This is a brave new world')
+    ft.capitalize(10, 15)
+    print(ft)
+
+    bft = BetterFormattedText('This is a brave new world')
+    bft.get_range(16, 19).capitalize = True
+    print(bft)