This is a modified version of the timing code by Patrick Altman "Try / Except Performance in Python: A Simple Test" http://paltman.com/2008/01/18/try-except-performance-in-python-a-simple-test/

altman.py

"""
This is a modified version of the timing code by
Patrick Altman "Try / Except Performance in Python: A Simple Test"
http://paltman.com/2008/01/18/try-except-performance-in-python-a-simple-test/
"""


import time

def time_me(function):
    def wrap(*arg):
        start = time.time()
        r = function(*arg)
        end = time.time()
        print("{} ({:.3f} ms)".format(function.__name__, (end-start)*1000))
        return r
    return wrap

# Not Existing
@time_me
def with_try(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        try:
            pass
        except KeyError:
            pass

@time_me
def with_try_exc(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        try:
            get = d['notexist']
        except KeyError:
            get = d['somekey']
            
@time_me
def without_try(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        if 'notexist' in d:
            pass
        else:
            pass


@time_me
def without_try_exc(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        if 'notexist' in d:
            get = d['notexist']
        else:
            get = d['somekey']

            
@time_me
def without_try_not(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        if 'notexist' not in d:
            pass
        else:
            pass
            
    
    
# Existing
@time_me
def exists_with_try(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        try:
            pass
        except KeyError:
            pass

@time_me
def exists_with_try_exc(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        try:
            get = d['somekey']
        except KeyError:
            get = d['somekey']
            
@time_me
def exists_without_try(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        if 'somekey' in d:
            pass
        else:
            pass


@time_me
def exists_without_try_exc(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        if 'somekey' in d:
            get = d['somekey']
        else:
            get = d['somekey']

            
@time_me
def exists_without_try_not_exc(iterations):
    d = {'somekey': 123}
    for i in range(0, iterations):
        if 'somekey' not in d:
            get = d['somekey']
        else:
            get = d['somekey']
        
        
print("The case where the key does not exist:")
print("1,000 iterations:")
with_try(1000)
with_try_exc(1000)
without_try(1000)
without_try_exc(1000)
without_try_not(1000)

print("\n100,000 iterations:")
with_try(100000)
with_try_exc(100000)
without_try(100000)
without_try_exc(100000)
without_try_not(100000)

print("\n1,000,000 iterations:")
with_try(1000000)
with_try_exc(1000000)
without_try(1000000)
without_try_exc(1000000)
without_try_not(1000000)

print("\n\nThe case where the key does exist:")
print("1,000 iterations:")
exists_with_try(1000)
exists_with_try_exc(1000)
exists_without_try(1000)
exists_without_try_exc(1000)
exists_without_try_not_exc(1000)

print("\n100,000 iterations:")
exists_with_try(100000)
exists_with_try_exc(100000)
exists_without_try(100000)
exists_without_try_exc(100000)
exists_without_try_not_exc(100000)

print("\n1,000,000 iterations:")
exists_with_try(1000000)
exists_with_try_exc(1000000)
exists_without_try(1000000)
exists_without_try_exc(1000000)
exists_without_try_not_exc(1000000)