Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #42440 > unrolled thread

executor.map() TypeError: zip argument #2 must support iteration

Back to article view | Back to comp.lang.python

Contents

  executor.map()    TypeError: zip argument #2 must support iteration iMath <redstone-cold@163.com> - 2013-03-31 21:45 -0700
    Re: executor.map()    TypeError: zip argument #2 must support iteration Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-04-01 07:48 +0000
      Re: executor.map()    TypeError: zip argument #2 must support iteration iMath <redstone-cold@163.com> - 2013-04-02 19:34 -0700

#42440 — executor.map() TypeError: zip argument #2 must support iteration

executor.map()    TypeError: zip argument #2 must support iteration

when I run it ,just generated TypeError: zip argument #2 must support iteration.
can anyone help me fix this problem ?

import time, concurrent.futures
lst100=[i for i in range(100)]

t1=time.clock()
print(list(map(str,lst100)))
t2=time.clock()
print(t2-t1)

t3=time.clock()
with concurrent.futures.ThreadPoolExecutor(max_workers=100) as executor:
    future_to_url = executor.map(str,lst100, 60)
    print(list(future_to_url))
t4=time.clock()
print(t4-t3)

[toc] | [next] | [standalone]

#42448

On Sun, 31 Mar 2013 21:45:21 -0700, iMath wrote:

> executor.map()    TypeError: zip argument #2 must support iteration
> 
> when I run it ,just generated TypeError: zip argument #2 must support
> iteration. can anyone help me fix this problem ?

Yes. Read the error message, and inspect the line that is in error. You 
have:

>     future_to_url = executor.map(str,lst100, 60)

executor.map has three arguments:

Arg 0: str
Arg 1: list of 100 ints
Arg 2: int 60

Argument 2, the number 60, does not support iteration, since it is an int.

Now read the docs for map. At the interactive interpreter, do this:

py> from concurrent.futures import ThreadPoolExecutor
py> help(ThreadPoolExecutor.map)


and you will see the following documentation:

map(self, fn, *iterables, timeout=None)
    Returns a iterator equivalent to map(fn, iter).

    Args:
        fn: A callable that will take take as many arguments as there are
            passed iterables.
        timeout: The maximum number of seconds to wait. If None, then
            there is no limit on the wait time.


Notice that the iterables argument is prefixed with * symbol. That means 
that it collects all the remaining positional arguments, which means that 
the timeout argument is keyword only.

So try this:


future_to_url = executor.map(str, lst100, timeout=60)


-- 
Steven

[toc] | [prev] | [next] | [standalone]

#42619

在 2013年4月1日星期一UTC+8下午3时48分34秒，Steven D'Aprano写道：
> On Sun, 31 Mar 2013 21:45:21 -0700, iMath wrote:
> 
> 
> 
> > executor.map()    TypeError: zip argument #2 must support iteration
> 
> > 
> 
> > when I run it ,just generated TypeError: zip argument #2 must support
> 
> > iteration. can anyone help me fix this problem ?
> 
> 
> 
> Yes. Read the error message, and inspect the line that is in error. You 
> 
> have:
> 
> 
> 
> >     future_to_url = executor.map(str,lst100, 60)
> 
> 
> 
> executor.map has three arguments:
> 
> 
> 
> Arg 0: str
> 
> Arg 1: list of 100 ints
> 
> Arg 2: int 60
> 
> 
> 
> Argument 2, the number 60, does not support iteration, since it is an int.
> 
> 
> 
> Now read the docs for map. At the interactive interpreter, do this:
> 
> 
> 
> py> from concurrent.futures import ThreadPoolExecutor
> 
> py> help(ThreadPoolExecutor.map)
> 
> 
> 
> 
> 
> and you will see the following documentation:
> 
> 
> 
> map(self, fn, *iterables, timeout=None)
> 
>     Returns a iterator equivalent to map(fn, iter).
> 
> 
> 
>     Args:
> 
>         fn: A callable that will take take as many arguments as there are
> 
>             passed iterables.
> 
>         timeout: The maximum number of seconds to wait. If None, then
> 
>             there is no limit on the wait time.
> 
> 
> 
> 
> 
> Notice that the iterables argument is prefixed with * symbol. That means 
> 
> that it collects all the remaining positional arguments, which means that 
> 
> the timeout argument is keyword only.
> 
> 
> 
> So try this:
> 
> 
> 
> 
> 
> future_to_url = executor.map(str, lst100, timeout=60)
> 
> 
> 
> 
> 
> -- 
> 
> Steven

thanks for  clarification.I thought argument 2 is lst100

[toc] | [prev] | [standalone]

Back to top | Article view | comp.lang.python

csiph-web