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strang thing:

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  strang thing: "守株待兔" <1248283536@qq.com> - 2011-09-06 16:18 +0800
    Re: strang thing: Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-09-13 13:28 +1000
      Re: strang thing: Chris Angelico <rosuav@gmail.com> - 2011-09-13 13:42 +1000

#12818 — strang thing:

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i found stange thing that i can't solve
import os
import  csv

for  name  in   os.listdir('/tmp/quote/'):
    filename='/tmp/quote/'+name
    file = open(filename,'r')
    file.readline()      
    for row in csv.reader(file):
                print   row[0], row[1], row[2], row[3],row[4], row[5], row[6]

it's ok,
when i  add    (date,open,high,low,close,vol,adjclose) = (row[0], row[1], row[2], row[3],row[4], row[5], row[6])
change the code into 
import os
import  csv

for  name  in   os.listdir('/tmp/quote/'):
    filename='/tmp/quote/'+name
    file = open(filename,'r')
    file.readline()      
    for row in csv.reader(file):
            (date,open,high,low,close,vol,adjclose) = (row[0], row[1], row[2], row[3],row[4], row[5], row[6])
            print   row[0], row[1], row[2], row[3],row[4], row[5], row[6]


the wrong  output is :
    file = open(filename,'r')
TypeError: 'str' object is not callable

i don't know why??

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#13208

(I sent this reply a week ago, but it seems to have disappeared. So trying
again.)


On Tue, 6 Sep 2011 06:18 pm 守株待兔 wrote:

> when i  add    (date,open,high,low,close,vol,adjclose) = (row[0], row[1],
> row[2], row[3],row[4], row[5], row[6]) change the code into

Here you define a new variable called "open", which has the value of row[1].
This shadows (hides) the built-in function also called "open", so later
when you do this:

>     file = open(filename,'r')
> TypeError: 'str' object is not callable

Python uses your string variable "open" instead of the built-in function.

The best solution is to avoid using the name "open", instead call it "open_"
(underscore at the end is the usual convention to avoid shadowing
built-ins). Or "open_value" or any other appropriate name.

Another solution is to save a reference to the open built-in first:

my_open = open
open = "something"
file = my_open("filename", "r")




-- 
Steven

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#13209

On Tue, Sep 13, 2011 at 1:28 PM, Steven D'Aprano
<steve+comp.lang.python@pearwood.info> wrote:
> The best solution is to avoid using the name "open", instead call it "open_"
> (underscore at the end is the usual convention to avoid shadowing
> built-ins). Or "open_value" or any other appropriate name.
>

This is why every good programmer keeps a thesaurus handy. I just now
had a "concept collision" on the word 'cancel', and did a quick search
to come up with 'annul' as an alternative. Although in this case I
didn't search my thesaurus, I actually looked for Magic: The Gathering
cards... yeah, I'm a nerd, aren't you? :)

There's lots of synonyms for open, and it's entirely possible that one
will work. Otherwise, Steven's other solution works just fine too, and
you can go humorous with that too:

sesame = open
open = "something"
file = sesame("filename", "r")

ChrisA

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