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Python EAFP vs LBYL speeds
import reusables
@reusables.time_it()
def test_lbyl(messages):
out = []
for _ in range(10000):
if messages and messages[0] and len(messages[0]) >= 3:
out.append(messages[0][2])
return out
@reusables.time_it()
def test_eafp(messages):
out = []
for _ in range(10000):
try:
out.append(messages[0][2])
except IndexError:
pass
return out
if __name__ == '__main__':
messages = [["hi there", "how are you?"]]
assert len(test_lbyl(messages)) == len(test_eafp(messages))
messages[0].append("I'm doing fine")
assert len(test_lbyl(messages)) == len(test_eafp(messages))
# LBYL is faster if the list isn't long enough, avoid an error and an attmepted append statement
# Function 'test_lbyl' took a total of 0.0016206308322832311 seconds - args: ([['hi there', 'how are you?']],)
# Function 'test_eafp' took a total of 0.0030271251617317893 seconds - args: ([['hi there', 'how are you?']],)
# EAFP is faster when the success path is more common, avoiding the costly lookups
# Function 'test_lbyl' took a total of 0.0027111909965087614 seconds - args: ([['hi there', 'how are you?', "I'm doing fine"]],)
# Function 'test_eafp' took a total of 0.001411011977187686 seconds - args: ([['hi there', 'how are you?', "I'm doing fine"]],)
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