Merge pull request #606 from realpython/python-set-comprehension

Sample code for the article on set comprehension

python-set-comprehension/README.md

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+# Python Set Comprehensions: How and When to Use Them
+
+This folder provides the code examples for the Real Python tutorial [Python Set Comprehensions: How and When to Use Them](https://realpython.com/python-set-comprehension/).

python-set-comprehension/colors.py

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+colors = {"blue", "red", "green", "orange", "green"}
+print(colors)
+colors.add("purple")
+print(colors)

python-set-comprehension/complex_expression.py

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+numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+
+print({number**2 if number % 2 == 0 else number**3 for number in numbers})
+
+result_set = set()
+for number in numbers:
+    if number % 2 == 0:
+        value = number**2
+    else:
+        value = number**3
+    result_set.add(value)
+
+print(result_set)

python-set-comprehension/emails.py

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+emails = {
+    " [email protected] ",
+    "[email protected]",
+    "[email protected]",
+    "[email protected]",
+    " [email protected]",
+    "[email protected]",
+}
+
+print({email.strip().lower() for email in emails})

python-set-comprehension/filter_emails.py

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+emails_set = {
+    "[email protected]",
+    "[email protected]",
+    "[email protected]",
+    "[email protected]",
+    "[email protected]",
+}
+
+print({email for email in emails_set if email.endswith(".com")})

python-set-comprehension/matrix.py

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+matrix = [
+    [9, 3, 8, 3],
+    [4, 5, 2, 8],
+    [6, 4, 3, 1],
+    [1, 0, 4, 5],
+]
+
+print({value**2 for row in matrix for value in row})

python-set-comprehension/text.py

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+unique_words = set()
+text = """
+Beautiful is better than ugly
+Explicit is better than implicit
+Simple is better than complex
+Complex is better than complicated
+""".lower()
+
+for word in text.split():
+    unique_words.add(word)
+
+print(unique_words)
+
+print(set(text.split()))
+
+unique_words = {word for word in text.split()}
+
+print(unique_words)

python-set-comprehension/tools.py

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+tools = ["Python", "Django", "Flask", "pandas", "NumPy"]
+tools_set = {tool.lower() for tool in tools}
+
+print(tools_set)
+print("python".lower() in tools_set)
+print("Pandas".lower() in tools_set)
+print("Numpy".lower() in tools_set)