Sample code for the membership operators article

Author: lpozo

python-in-operator/README.md

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+# Python's "in" and "not in" Operators: Check for Membership
+
+This folder provides the code examples for the article [Python's "in" and "not in" Operators: Check for Membership](https://realpython.com/python-in-operator/).

python-in-operator/performance.py

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+from timeit import timeit
+
+a_list = list(range(100_000))
+a_set = set(range(100_000))
+
+
+list_time = timeit("-1 in a_list", number=1, globals=globals())
+set_time = timeit("-1 in a_set", number=1, globals=globals())
+
+print(f"Sets are {(list_time / set_time):.2f} times faster than Lists")

python-in-operator/permissions.py

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+class User:
+    def __init__(self, username, permissions):
+        self.username = username
+        self.permissions = permissions
+
+
+admin = User("admin", "wrx")
+john = User("john", "rx")
+
+
+def has_permission(user, permission):
+    return permission in user.permissions
+
+
+has_permission(admin, "w")
+has_permission(john, "w")

python-in-operator/stack.py

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+class Stack:
+    def __init__(self):
+        self.items = []
+
+    def push(self, item):
+        self.items.append(item)
+
+    def pop(self):
+        return self.items.pop()
+
+    # def __iter__(self):
+    #     yield from self.items
+
+    def __contains__(self, item):
+        return item in self.items
+
+    # def __getitem__(self, index):
+    #     return self.items[index]

python-in-operator/users.py

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+username = input("Username: ")
+password = input("Password: ")
+
+users = [("john", "secret"), ("jane", "secret"), ("linda", "secret")]
+
+if (username, password) in users:
+    print(f"Hi {username}, you're logged in!")
+else:
+    print("Wrong username or password")