From 2cc490f3f27f84a2c74caaab6ee367835d042135 Mon Sep 17 00:00:00 2001
From: Brandon Rozek <rozekbrandon@gmail.com>
Date: Wed, 8 Apr 2020 19:05:28 -0400
Subject: [PATCH] New Posts

---
 content/blog/copydecorator.md | 48 +++++++++++++++++++++++++++++++
 content/blog/pydataclass.md   | 29 +++++++++++++++++++
 content/blog/pygetset.md      | 53 +++++++++++++++++++++++++++++++++++
 3 files changed, 130 insertions(+)
 create mode 100644 content/blog/copydecorator.md
 create mode 100644 content/blog/pydataclass.md
 create mode 100644 content/blog/pygetset.md

diff --git a/content/blog/copydecorator.md b/content/blog/copydecorator.md
new file mode 100644
index 0000000..88710e0
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+++ b/content/blog/copydecorator.md
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+---
+title: "Quick Python: Copy Decorator"
+date: 2020-04-08T18:49:54-04:00
+draft: false
+tags: ["python"]
+---
+
+If you want to guarantee that your function doesn't modify any of the references and don't mind paying a price in memory consumption, here is a decorator you can easily add to your functions.
+
+```python
+from copy import deepcopy
+def copy_arguments(func):
+    def wrapper(*args, **kwargs):
+        new_args = deepcopy(args)
+        new_kwargs = deepcopy(kwargs)
+        return func(*new_args, **new_kwargs)
+    return wrapper
+```
+
+Example usage:
+
+```python
+@copy_arguments
+def modify1(xs):
+    for i, _ in enumerate(xs):
+        xs[i] *= 2
+```
+
+Comparison:
+
+```python
+def modify2(xs):
+    for i, _ in enumerate(xs):
+        xs[i] *= 2
+
+a = [1, 2, 3, 4, 5]
+b = [1, 2, 3, 4, 5]
+modify1(a)
+modify2(a)
+print(a)
+print(b)
+```
+
+```
+[1, 2, 3, 4, 5]
+[2, 4, 6, 8, 10]
+```
+
diff --git a/content/blog/pydataclass.md b/content/blog/pydataclass.md
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+---
+title: "Quick Python: Dataclasses"
+date: 2020-04-08T18:59:48-04:00
+draft: false
+tags: ["python"]
+---
+
+Python 3.7 and above have a feature called dataclasses. This allows us to reduce boilerplate code by removing the need to create a whole constructor and providing a sensible `__repr__` function.
+
+```python
+from dataclasses import dataclass
+
+@dataclass
+class Person:
+    name: str
+    age: int
+```
+
+Usage:
+
+```python
+p = Person("Bob", 30)
+print(p)
+```
+
+```
+Person(name='Bob', age=20)
+```
+
diff --git a/content/blog/pygetset.md b/content/blog/pygetset.md
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+---
+title: "Quick Python: Getters and Setters"
+date: 2020-04-08T18:15:21-04:00
+draft: false
+tags: ["python"]
+---
+
+One of the hidden gems in Python classes are seamless getters and setters. I discovered this through the book [Effective Python by Brett Slatkin](https://effectivepython.com/). Though the example I'll use is different and shorter than the one he uses in his book.
+
+Let's create a class representing a person. The only information we're going to store is their age and we'll make it optional to provide it.
+
+```python
+class Person:
+    def __init__(self, age=None):
+        self._age = None
+    @property
+    def age(self):
+        if self._age is None:
+            raise ValueError("age must be set before accessing it.")
+        return self._age
+   	@age.setter
+    def age(self, age):
+        if age < 0:
+            raise ValueError("age must be at least zero.")
+        self._age = age
+```
+
+The second function in the class decorated by `@property` will be the getter function for the attribute `_age`. The name of the function will be what we expect the user to access it as. The setter is then decorated with `age.setter` where `age` is the name of the attribute. As such the name chosen in the getter function name, setter function name, and decorator must all match.
+
+Now let's try using it
+
+```python
+bobby = Person()
+bobby.age
+```
+
+```
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+  File "/home/user/test.py", line 7, in age
+    raise ValueError("age must first be set before accessing it")
+ValueError: age must first be set before accessing it
+```
+
+```python
+bobby.age = 5
+bobby.age
+```
+
+```
+5
+```
+