Hello -
Last night I wrote my first code in Python -- a little
producer/consumer toy to help me begin to understand things. The
"Library" only has a few books. You can choose how many Readers are
trying to check out the books. When no books are available, they have
to wait until some other Reader returns one. Readers are assigned
random reading speeds and wait times between
It runs fine, but I have a few questions about it.
1) Is this good Python code? What should be changed to make it more
Pythonesque?
2) Anybody know how to alter the "while 1: pass" section to make the
app stoppable?
3) The synchronization I'm using works, but is there a better way to do
it?
Thanks for any insight/pointers, etc.
Also, for any newbies like me, feel free to post variations of this
code. In the next version, I'm going to make it so that readers can't
check out the same book twice.
Here's the code:
#!/usr/bin/python
# Filename: Library.py
# author: MWT
# 5 Feb, 2006
import thread
import time
import threading
import random
class Library:
#The goal here is to create a synchronized list of books
def __init__(self):
self.stacks = ["Heart of Darkness", "Die Verwandlung", "Lord of
the Flies", "For Whom the Bell Tolls", "Dubliners" , "Cyrano de
Bergerac"]
self.cv = threading.Condi tion()
def checkOutBook(se lf):
#remove book from the front of the list, block if no books are
available
self.cv.acquire ()
while not len(self.stacks ) > 0:
self.cv.wait()
print "waiting for a book..."
bookName = self.stacks.pop (0)
self.cv.release ()
return bookName
def returnBook(self , nameOfBook):
#put book at the end of the list, notify that a book is available
self.cv.acquire ()
self.stacks.app end(nameOfBook)
self.cv.notify( )
self.cv.release ()
class Reader(threadin g.Thread):
def __init__(self, library, name, readingSpeed, timeBetweenBook s):
threading.Threa d.__init__(self )
self.library = library
self.name = name
self.readingSpe ed = readingSpeed
self.timeBetwee nBooks = timeBetweenBook s
self.bookName = ""
def run(self):
while 1:
self.bookName = self.library.ch eckOutBook()
print self.name, "reading", self.bookName
time.sleep(self .readingSpeed)
print self.name, "done reading", self.bookName
self.library.re turnBook(self.b ookName)
self.bookName = ""
time.sleep(self .timeBetweenBoo ks)
if __name__=="__ma in__":
library = Library()
readers = input("Number of Readers?")
for i in range(1,readers ):
newReader = Reader(library, "Reader" + str (i),
random.randint( 1,7), random.randint( 1,7))
newReader.start ()
while 1: pass
Last night I wrote my first code in Python -- a little
producer/consumer toy to help me begin to understand things. The
"Library" only has a few books. You can choose how many Readers are
trying to check out the books. When no books are available, they have
to wait until some other Reader returns one. Readers are assigned
random reading speeds and wait times between
It runs fine, but I have a few questions about it.
1) Is this good Python code? What should be changed to make it more
Pythonesque?
2) Anybody know how to alter the "while 1: pass" section to make the
app stoppable?
3) The synchronization I'm using works, but is there a better way to do
it?
Thanks for any insight/pointers, etc.
Also, for any newbies like me, feel free to post variations of this
code. In the next version, I'm going to make it so that readers can't
check out the same book twice.
Here's the code:
#!/usr/bin/python
# Filename: Library.py
# author: MWT
# 5 Feb, 2006
import thread
import time
import threading
import random
class Library:
#The goal here is to create a synchronized list of books
def __init__(self):
self.stacks = ["Heart of Darkness", "Die Verwandlung", "Lord of
the Flies", "For Whom the Bell Tolls", "Dubliners" , "Cyrano de
Bergerac"]
self.cv = threading.Condi tion()
def checkOutBook(se lf):
#remove book from the front of the list, block if no books are
available
self.cv.acquire ()
while not len(self.stacks ) > 0:
self.cv.wait()
print "waiting for a book..."
bookName = self.stacks.pop (0)
self.cv.release ()
return bookName
def returnBook(self , nameOfBook):
#put book at the end of the list, notify that a book is available
self.cv.acquire ()
self.stacks.app end(nameOfBook)
self.cv.notify( )
self.cv.release ()
class Reader(threadin g.Thread):
def __init__(self, library, name, readingSpeed, timeBetweenBook s):
threading.Threa d.__init__(self )
self.library = library
self.name = name
self.readingSpe ed = readingSpeed
self.timeBetwee nBooks = timeBetweenBook s
self.bookName = ""
def run(self):
while 1:
self.bookName = self.library.ch eckOutBook()
print self.name, "reading", self.bookName
time.sleep(self .readingSpeed)
print self.name, "done reading", self.bookName
self.library.re turnBook(self.b ookName)
self.bookName = ""
time.sleep(self .timeBetweenBoo ks)
if __name__=="__ma in__":
library = Library()
readers = input("Number of Readers?")
for i in range(1,readers ):
newReader = Reader(library, "Reader" + str (i),
random.randint( 1,7), random.randint( 1,7))
newReader.start ()
while 1: pass
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