List

  1. Create list

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    a = [0, 1, 2]
    a.append(3) # a = [0, 1, 2, 3]
    a += [4] # a = [0, 1, 2, 3, 4]

  2. List index

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for num,freq in collections.Counter(nums).items():
  print("num ", num, ", freq ", freq)
  buckets[-freq].append(num)
  1. Sort
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    intervals.sort(key=lambda x: x[0])

  • Random

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    random.random()

  • extend vs append
    We see that extend is semantically clearer, and that it can run much faster than append, when you intend to append each element in an iterable to a list.

    If you only have a single element (not in an iterable) to add to the list, use append.

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import timeit

>>> min(timeit.repeat(lambda: append([], "abcdefghijklmnopqrstuvwxyz")))
2.867846965789795
>>> min(timeit.repeat(lambda: extend([], "abcdefghijklmnopqrstuvwxyz")))
0.8060121536254883

https://stackoverflow.com/a/28119966/5133816