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-rw-r--r--wqflask/utility/chunks.py96
1 files changed, 96 insertions, 0 deletions
diff --git a/wqflask/utility/chunks.py b/wqflask/utility/chunks.py
new file mode 100644
index 00000000..9565fb96
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+++ b/wqflask/utility/chunks.py
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+from __future__ import absolute_import, print_function, division
+
+import math
+import time
+
+
+def divide_into_chunks(the_list, number_chunks):
+ """Divides a list into approximately number_chunks smaller lists
+
+ >>> divide_into_chunks([1, 2, 7, 3, 22, 8, 5, 22, 333], 3)
+ [[1, 2, 7], [3, 22, 8], [5, 22, 333]]
+ >>> divide_into_chunks([1, 2, 7, 3, 22, 8, 5, 22, 333], 4)
+ [[1, 2, 7], [3, 22, 8], [5, 22, 333]]
+ >>> divide_into_chunks([1, 2, 7, 3, 22, 8, 5, 22, 333], 5)
+ [[1, 2], [7, 3], [22, 8], [5, 22], [333]]
+ >>>
+
+ """
+ length = len(the_list)
+
+ if length == 0:
+ return [[]]
+
+ if length <= number_chunks:
+ number_chunks = length
+
+ chunksize = int(math.ceil(length / number_chunks))
+
+ chunks = []
+ for counter in range(0, length, chunksize):
+ chunks.append(the_list[counter:counter+chunksize])
+
+ return chunks
+
+def _confirm_chunk(original, result):
+ all_chunked = []
+ for chunk in result:
+ all_chunked.extend(chunk)
+ print("length of all chunked:", len(all_chunked))
+ assert original == all_chunked, "You didn't chunk right"
+
+
+def _chunk_test(divide_func):
+ import random
+ random.seed(7)
+
+ number_exact = 0
+ total_amount_off = 0
+
+ for test in range(1, 1001):
+ print("\n\ntest:", test)
+ number_chunks = random.randint(1, 20)
+ number_elements = random.randint(0, 100)
+ the_list = list(range(1, number_elements))
+ result = divide_func(the_list, number_chunks)
+
+ print("Dividing list of length {} into approximately {} chunks - got {} chunks".format(
+ len(the_list), number_chunks, len(result)))
+ print("result:", result)
+
+ _confirm_chunk(the_list, result)
+
+ amount_off = abs(number_chunks - len(result))
+ if amount_off == 0:
+ number_exact += 1
+ else:
+ total_amount_off += amount_off
+
+
+ print("\n{} exact out of {} [Total amount off: {}]".format(number_exact,
+ test,
+ total_amount_off))
+ assert number_exact == 558
+ assert total_amount_off == 1580
+ return number_exact, total_amount_off
+
+
+def _main():
+ info = dict()
+ #funcs = (("sam", sam_divide_into_chunks), ("zach", zach_divide_into_chunks))
+ funcs = (("only one", divide_into_chunks),)
+ for name, func in funcs:
+ start = time.time()
+ number_exact, total_amount_off = _chunk_test(func)
+ took = time.time() - start
+ info[name] = dict(number_exact=number_exact,
+ total_amount_off=total_amount_off,
+ took=took)
+
+ print("info is:", info)
+
+if __name__ == '__main__':
+ _main()
+ print("\nConfirming doctests...")
+ import doctest
+ doctest.testmod()