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python Programming Glossary: wisedjango - convert a list back to a queryset http://stackoverflow.com/questions/1058135/django-convert-a-list-back-to-a-queryset query and that would be redundant and very bad performance wise. What you can do Describe how the reputation field is calculated..
retrieve links from web page using python and beautiful soup http://stackoverflow.com/questions/1080411/retrieve-links-from-web-page-using-python-and-beautiful-soup class because it's a bit more efficient memory and speed wise if you know what you're parsing in advance. share improve this..
Python: tf-idf-cosine: to find document similarity http://stackoverflow.com/questions/12118720/python-tf-idf-cosine-to-find-document-similarity count features and apply TF IDF normalization and row wise euclidean normalization you can do it in one operation with.. . To get the first vector you need to slice the matrix row wise to get a submatrix with a single row tfidf 0 1 1x130088 sparse.. Sparse Row format scikit learn already provides pairwise metrics a.k.a. kernels in machine learning parlance that work..
Python subprocess.Popen “OSError: [Errno 12] Cannot allocate memory” http://stackoverflow.com/questions/1367373/python-subprocess-popen-oserror-errno-12-cannot-allocate-memory instance on the same server as you running amock. Memory wise we already know that subprocess.Popen uses fork clone under..
“Large data” work flows using pandas http://stackoverflow.com/questions/14262433/large-data-work-flows-using-pandas queries . Since pytables is optimized to operate on row wise which is what you query on we will create a table for each group..
Find unique rows in numpy.array http://stackoverflow.com/questions/16970982/find-unique-rows-in-numpy-array 1 a.shape 1 Also at least on my system performance wise it is on par or even better than the lexsort method a np.random.randint..
How can I quantify difference between two images? http://stackoverflow.com/questions/189943/how-can-i-quantify-difference-between-two-images as arrays scipy.misc.imread and calculate an element wise difference. Calculate the norm of the difference. However there.. the difference and its norms diff img1 img2 # elementwise for scipy arrays m_norm sum abs diff # Manhattan norm z_norm.. . arr is a SciPy array here so all operations are element wise def normalize arr rng arr.max arr.min amin arr.min return arr..
Python append() vs. + operator on lists, why do these give different results? http://stackoverflow.com/questions/2022031/python-append-vs-operator-on-lists-why-do-these-give-different-results the operator as others have shown here as well . It's not wise to do the opposite to try to mimic append with the operator..
Simple Python Challenge: Fastest Bitwise XOR on Data Buffers http://stackoverflow.com/questions/2119761/simple-python-challenge-fastest-bitwise-xor-on-data-buffers Python Challenge Fastest Bitwise XOR on Data Buffers Challenge Perform a bitwise XOR on two.. Bitwise XOR on Data Buffers Challenge Perform a bitwise XOR on two equal sized buffers. The buffers will be required.. from os import urandom from numpy import frombuffer bitwise_xor byte def slow_xor aa bb a frombuffer aa dtype byte b frombuffer..
Inverse Distance Weighted (IDW) Interpolation with Python http://stackoverflow.com/questions/3104781/inverse-distance-weighted-idw-interpolation-with-python Is creating my own implementation with the aid of scipy a wise choice python numpy scipy spatial interpolation share improve..
Creating a simple XML file using python http://stackoverflow.com/questions/3605680/creating-a-simple-xml-file-using-python if I want to create a simple XML file in python library wise The xml I want looks like root doc field1 name blah some value1..
How to improve performance of this code? http://stackoverflow.com/questions/4295799/how-to-improve-performance-of-this-code What should I do to improve this code Mostly performance wise any other suggestions are welcome also . Thanks. python performance..
Modulus operation with negatives values - weird thing? http://stackoverflow.com/questions/43775/modulus-operation-with-negatives-values-weird-thing According to my python interpreter is 3 but do you have a wise explanation for this I've read that in some languages the result..
Try/catch or validation for speed? http://stackoverflow.com/questions/5589532/try-catch-or-validation-for-speed component. Vector and Vector addition required component wise addition. This code is being used for a raytracer so any speed..
http://stackoverflow.com/questions/7933596/django-dynamic-model-fields database. However hstore is not ideal performance wise especially if you are going to end up storing thousands of items..
How to read large file, line by line in python http://stackoverflow.com/questions/8009882/how-to-read-large-file-line-by-line-in-python TIA Chakri EDIT The purpose is to calculate pair wise string similarity. Meaning for each line in file I want to calculate..
How to get line count cheaply in Python? http://stackoverflow.com/questions/845058/how-to-get-line-count-cheaply-in-python What is the most efficient way both memory and time wise At the moment I do def file_len fname with open fname as f for..
Python out of memory on large CSV file (numpy) http://stackoverflow.com/questions/8956832/python-out-of-memory-on-large-csv-file-numpy that I try to read with python I need the median column wise. from numpy import def data return genfromtxt 'All.csv' delimiter..
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