quick newbie syntax question

[Robocop]

Is it possible to do something like this syntactically:

year = '2008'
month = '09'
limit = '31'
for i in range(1,limit):
temp = Table.objects.filter(date = year'-'month'-'i) <----screwed
up syntax
...do something with temp
return

I know that the syntax within the filter statement is wrong. Is it
even possible to do something like that? Any help is always
appreciated.

 

[Chris Rebert]

Is it possible to do something like this syntactically:

year = '2008'
month = '09'
limit = '31'
for i in range(1,limit):

This previous line will fail. range() takes numbers, not strings.
Change 'limit' to an int.

temp = Table.objects.filter(date = year'-'month'-'i) <----screwed

I believe you're looking for the string formatting syntax, to wit:

temp = Table.objects.filter( date="%s-%s-%s" % (year, month, i) )

Note that you can let 'year' and 'month' be integers now, as they will
be converted to strings for you automatically.

Cheers,
Chris

 

[Robocop]

oops! Sorry about that, i should have just copied my code directly.
I actually did specify an int in range:
The code is currently failing due to the syntax in the filter,
particularly the section "date = year'-'month'-'i"

 

[Larry Bates]

oops! Sorry about that, i should have just copied my code directly.
I actually did specify an int in range:

The code is currently failing due to the syntax in the filter,
particularly the section "date = year'-'month'-'i"

I believe you want something more like

date = "%s-%s-%s" % (year, month, i)

but then again I can't quite figure out what is is that you are wanting to do
(Note: September doesn't have 31 days).

Where did Table object come from and what does the table.objects.filter method
do and what are the appropriate arguments to that method? If it was "my"
method, and I wanted to use it this way, I would think about changing it so that
it accepted a filtering function and returned only those objects that passed the
filtering function:

def myFilter(obj):
return (obj.date >= '2008-09-01' and obj.date <= '2008-09-30')

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

def filter(filterFunc):
return [x for x in self.objects if filterFunc(x)]


Then

temp = Table.objects.filter(myFilter)

temp is a list of objects you can act on.

-Larry

 

[Robocop]

date = "%s-%s-%s" % (year, month, i) is exactly what i'd like to do.

The Table object will just be a mysql table, and the filter function
will yield a list filtered for those dates.
For my purposes the limit variable will not be static, depending on
which day of the month it is i will only want it to iterate up to that
date in the month (i use 31 here as an example as i would want it to
iterate through the 30th of september). Thanks for the input!

oops!   Sorry about that, i should have just copied my code directly.
I actually did specify an int in range:

The code is currently failing due to the syntax in the filter,
particularly the section "date = year'-'month'-'i"

I believe you want something more like

date = "%s-%s-%s" % (year, month, i)

but then again I can't quite figure out what is is that you are wanting to do
(Note: September doesn't have 31 days).

Where did Table object come from and what does the table.objects.filter method
do and what are the appropriate arguments to that method?  If it was "my"
method, and I wanted to use it this way, I would think about changing it so that
it accepted a filtering function and returned only those objects that passed the
filtering function:

def myFilter(obj):
     return (obj.date >= '2008-09-01' and obj.date <= '2008-09-30')

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

     def filter(filterFunc):
         return [x for x in self.objects if filterFunc(x)]

Then

temp = Table.objects.filter(myFilter)

temp is a list of objects you can act on.

-Larry

 

[Steven D'Aprano]

oops! Sorry about that, i should have just copied my code directly. I
actually did specify an int in range:

The code is currently failing due to the syntax in the filter,
particularly the section "date = year'-'month'-'i"

Name binding ("date = something") is not an expression and must be on a
line of its own. So you can't do something like:

function(y=x+1, 2, 3)

(Except of course for function default values, which is not quite the
same thing.)