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  1. PO
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    <p>This is why your OS has multiprocessing pipelines.</p> <pre><code>collapse.py sometweetfile | filter.py | user_id.py | user_split.py -d some_directory </code></pre> <p>collapse.py</p> <pre><code>import sys with open("source","r") as theFile: tweet = {} for line in theFile: rec_type, content = line.split('\t') if rec_type in tweet: t, u, w = tweet.get('T',''), tweet.get('U',''), tweet.get('W','') result= "{0}\t{1}\t{2}".format( t, u, w ) sys.stdout.write( result ) tweet= {} tweet[rec_type]= content t, u, w = tweet.get('T',''), tweet.get('U',''), tweet.get('W','') result= "{0}\t{1}\t{2}".format( t, u, w ) sys.stdout.write( result ) </code></pre> <p>filter.py</p> <pre><code>import sys for tweet in sys.stdin: t, u, w = tweet.split('\t') if 'No Post Title' in t: continue sys.stdout.write( tweet ) </code></pre> <p>user_id.py</p> <pre><code>import sys import urllib for tweet in sys.stdin: t, u, w = tweet.split('\t') path=urlparse(w).path.strip('/') result= "{0}\t{1}\t{2}\t{3}".format( t, u, w, path ) sys.stdout.write( result ) </code></pre> <p>user_split.py</p> <pre><code>users = {} for tweet in sys.stdin: t, u, w, user = tweet.split('\t') if user not in users: # May run afoul of open file limits... users[user]= open(some_directory+user,"w") users[user].write( tweet ) users[user].flush( tweet ) for u in users: users[u].close() </code></pre> <p>Wow, you say. What a lot of code.</p> <p>Yes. But. It spreads out among ALL the processing cores you own and it all runs concurrently. Also, when you connect stdout to stdin through a pipe, it's really only a shared buffer: there's no physical I/O occurring.</p> <p>It's amazingly fast to do things this way. That's why the <strong>*Nix</strong> operating systems work that way. This is what you need to do for real speed.</p> <hr> <p>The LRU algorithm, FWIW.</p> <pre><code> if user not in users: # Only keep a limited number of files open if len(users) &gt; 64: # or whatever your OS limit is. lru, aFile, u = min( users.values() ) aFile.close() users.pop(u) users[user]= [ tolu, open(some_directory+user,"w"), user ] tolu += 1 users[user][1].write( tweet ) users[user][1].flush() # may not be necessary users[user][0]= tolu </code></pre>
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    1. POProcessing a huge file (9.1GB) and processing it faster -- Python
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    1. POProcessing a huge file (9.1GB) and processing it faster -- Python
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    1. COThanks a lot for your solution . Getting a sys.excepthook problem, i guess it has something to do with the synchronization. Trying to google and find out solution to that. but your solution is awesome, never thought on those lines at all :(
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    2. CO"sys.excepthook problem"? "synchronization"? Can you be more specific?
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    3. COYeah sure. I run the commands as you have mentioned in the reply. It shows the following : bash: ./user_id.py: Permission denied bash: ./filter.py: Permission denied bash: ./user_split.py: Permission denied close failed in file object destructor: Error in sys.excepthook: Original exception was: Thats all. This is what i get when executed.
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