"""Speed tester for Python list lookup.
"""

import timeit
NUMBER = 10000

setup = """
Start, Middle, End = map(tuple, ('Start', 'Middle', 'End'))
ls = [Start] + [tuple('Foo')] * 500 + [Middle] + [tuple('Bar')] * 500 + [End]
"""

print("Time in us to find an exact match (begin, middle, end):")
print(
    min(timeit.repeat('Start in ls', setup, number=NUMBER))/NUMBER*1e6,
    min(timeit.repeat('Middle in ls', setup, number=NUMBER))/NUMBER*1e6,
    min(timeit.repeat('End in ls', setup, number=NUMBER))/NUMBER*1e6,
    )

print("Time in us to find an equal match (begin, middle, end):")
print(
    min(timeit.repeat('tuple("Start") in ls', setup, number=NUMBER))/NUMBER*1e6,
    min(timeit.repeat('tuple("Middle") in ls',setup, number=NUMBER))/NUMBER*1e6,
    min(timeit.repeat('tuple("End") in ls', setup, number=NUMBER))/NUMBER*1e6,
    )

print("Time if not found:")
print(min(timeit.repeat('tuple("X") in ls', setup, number=NUMBER))/NUMBER*1e6)


print("And now for an object that has no __equal__:")
setup = """
class Thing: pass
Start, Middle, End = Thing(), Thing(), Thing()
ls = [Start] + [Thing()] * 500 + [Middle] + [Thing()] * 500 + [End]
"""

print("Time in us to find a thing (begin, middle, end):")
print(
    min(timeit.repeat('Start in ls', setup, number=NUMBER))/NUMBER*1e6,
    min(timeit.repeat('Middle in ls', setup, number=NUMBER))/NUMBER*1e6,
    min(timeit.repeat('End in ls', setup, number=NUMBER))/NUMBER*1e6,
    )

print("Time if not found:")
print(min(timeit.repeat('Thing() in ls', setup, number=NUMBER))/NUMBER*1e6)



"""Text for issue:
When doing an operation that does linear search through a container, the interpreter check all items one by one, first checking identity and then equality.
In python, you effectively get:
class myContainer:
  def __contains__(self, obj):
    for i in range(len(self)):
      if self[i] is obj: return True
      if self[i]==obj: return True
    return False

My proposal is to change this to:
class myContainer:
  def __contains__(self, obj):
    for i in range(len(self)):
      if self[i] is obj: return True
    for i in range(len(self)):
      if self[i]==obj: return True
    return False

The net effect would be approximately:
- if the object is exactly in the container, the speedup is 50%.
- if the object is not in the container, there is no difference.
- if an object is in the container that is equal to the object, it will be slower, but not much.
"""