updates

Author: Kevin Lu

.pytest_cache/v/cache/nodeids

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+[]

.pytest_cache/v/cache/stepwise

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+[]

Lesson 4/itertools.py

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 # demonstration of commonly used tools in itertools
+# commonly used ones from https://docs.python.org/2/library/itertools.html#module-itertools
+# do not memorize them but just remember they exist when you practice
+# 
+
 from itertools import *
+
+# for repetition
+
+# count
 for i in count():
-    print(i)
+     if i == 10:
+          break
+     print(i)
+
+# cycle
+n = 0
+for i in cycle('ABCD'):
+     print(i)
+     n += 1
+     if n > 8:
+          break
+
+# repeat
+for i in repeat('X', 3):
+     print(i)
+
+# combinatorical functions
+
+# fun fact: the reason it is called a product is since this is precisely what you would arrive
+# at if you expanded (A + B + C)(X + Y + Z)
+print(list(product('ABC', 'XYZ')))
+
+print(list(permutations('ABCD', 2)))
+
+print(list(combinations('ABCD', 2)))
+
+# for iterators
+
+print(list(starmap(lambda a, b: a > b, [(1,2), (4,5), (10, 1)])))
+
+# HW #1: find out what tee() does from https://docs.python.org/3/library/itertools.html#itertools.tee 
 
+# functools: https://docs.python.org/3/library/functools.html
+# operators: https://docs.python.org/3/library/operator.html