equivalent functions?

[wietse]

Hello,

I'm reading "Text processing in Python" by David Mertz. In there he
defines a function

apply_each  = lambda fns, args=[]: map(apply, fns, [args]*len(fns))

I thought that this would be equivalent to:

apply_each = lambda fns, args=[]: [f(args) for f in fns]

Can anybody confirm this? If not, how are they different?
Thanks,
Wietse

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Re: equivalent functions?

[wietse]

Got it! Thanks for your time.

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Re: equivalent functions?

[wietse]

Got it! Thanks for your time.

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instance variable weirdness

[wietse]

Hello,

I have written the following script to illustrate a problem in my code:

class BaseClass(object):
def __init__(self):
self.collection = []

class MyClass(BaseClass):
def __init__(self, name, collection=[]):
BaseClass.__init__(self)
self.name = name
self.collection = collection

if __name__ == '__main__':
seq = []
inst = None
for i in xrange(5):
inst = MyClass(str(i))
inst.collection.append(i)
seq.append(inst)
inst = None
for i in xrange(5):
inst = MyClass(str(i)+'~', [])
inst.collection.append(i)
seq.append(inst)
inst = None
for i in seq:
print "Instance '%s'; collection = %s" % (i.name,
str(i.collection))

The output I get is:
>>>
Instance '0'; collection = [0, 1, 2, 3, 4]
Instance '1'; collection = [0, 1, 2, 3, 4]
Instance '2'; collection = [0, 1, 2, 3, 4]
Instance '3'; collection = [0, 1, 2, 3, 4]
Instance '4'; collection = [0, 1, 2, 3, 4]
Instance '0~'; collection = [0]
Instance '1~'; collection = [1]
Instance '2~'; collection = [2]
Instance '3~'; collection = [3]
Instance '4~'; collection = [4]
>>>

I don't understand why the first loop doesn't give the same result as
the second loop. Can somebody enlighten me?

Wietse

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