Recitation01 Notes
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(New page: ==== Profiling list operations ==== <pre> # Author: Matthew Ng # Last update: September 08, 2008 # # Profile adding items to a list using "+" vs. extend() items = [[i] for i in range(50000...) |
(→Rewriting count_frequency in document distance problem) |
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==== Rewriting count_frequency in document distance problem ==== | ==== Rewriting count_frequency in document distance problem ==== | ||
<pre> | <pre> | ||
| - | |||
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def count_frequency_mod(word_list): | def count_frequency_mod(word_list): | ||
""" | """ | ||
| Line 38: | Line 35: | ||
D[new_word] = 1 | D[new_word] = 1 | ||
return D.items() | return D.items() | ||
| + | </pre> | ||
Revision as of 04:14, 11 September 2008
Profiling list operations
# Author: Matthew Ng
# Last update: September 08, 2008
#
# Profile adding items to a list using "+" vs. extend()
items = [[i] for i in range(50000)]
def list_concat():
L = []
for item in items:
L = L + item
def list_extend():
L = []
for item in items:
L.extend(item)
import profile
profile.run(list_concat())
profile.run(list_extend())
Rewriting count_frequency in document distance problem
def count_frequency_mod(word_list):
"""
Return a list giving pairs of form: (word,frequency)
"""
D = {}
for new_word in word_list:
if D.has_key(new_word):
D[new_word] = D[new_word]+1
else:
D[new_word] = 1
return D.items()
