Re: Temporary variables in list comprehensions

2017-01-09 Thread Serhiy Storchaka
On 09.01.17 12:46, Paul Rubin wrote: Serhiy Storchaka writes: gen = (expensive_calculation(x) for x in data) result = [(tmp, tmp + 1) for tmp in gen] result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)] Yes, of course, but only in the case of one-argument function expensive_

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Ethan Furman wrote, on January 09, 2017 10:06 PM > > On 01/09/2017 08:51 PM, Deborah Swanson wrote: > > Ethan Furman wrote, on January 09, 2017 8:01 PM > > >> As I said earlier, I admire your persistence -- but take some time > >> and learn the basic vocabulary as that will make it much easier f

Re: Is enum iteration order guaranteed?

2017-01-09 Thread Steven D'Aprano
On Tuesday 10 January 2017 16:55, Ethan Furman wrote: > On 01/09/2017 09:18 PM, Steven D'Aprano wrote: > >> The docs say that enums can be iterated over, but it isn't clear to me >> whether they are iterated over in definition order or value order. >> >> If I have: >> >> class MarxBros(Enum): >>

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Ethan Furman
On 01/09/2017 08:51 PM, Deborah Swanson wrote: Ethan Furman wrote, on January 09, 2017 8:01 PM As I said earlier, I admire your persistence -- but take some time and learn the basic vocabulary as that will make it much easier for you to ask questions, and for us to give you meaningful answers.

Re: Is enum iteration order guaranteed?

2017-01-09 Thread Ethan Furman
On 01/09/2017 09:18 PM, Steven D'Aprano wrote: The docs say that enums can be iterated over, but it isn't clear to me whether they are iterated over in definition order or value order. If I have: class MarxBros(Enum): GROUCHO = 999 CHICO = 5 HARPO = 11 ZEPPO = auto() G

Re: Enum with only a single member

2017-01-09 Thread Jussi Piitulainen
Steven D'Aprano writes: > Is it silly to create an enumeration with only a single member? That > is, a singleton enum? > > from enum import Enum > > class Unique(Enum): > FOO = auto() > > > The reason I ask is that I have two functions that take an enum > argument. The first takes one of three

Is enum iteration order guaranteed?

2017-01-09 Thread Steven D'Aprano
The docs say that enums can be iterated over, but it isn't clear to me whether they are iterated over in definition order or value order. If I have: class MarxBros(Enum): GROUCHO = 999 CHICO = 5 HARPO = 11 ZEPPO = auto() GUMMO = -1 GROUCHO, CHICO, HARPO, ZEPPO, GUMMO = list(

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Erik wrote, on January 09, 2017 8:06 PM > > On 10/01/17 03:02, Deborah Swanson wrote: > > Erik wrote, on January 09, 2017 5:47 PM > >> IIRC, you create it using a list comprehension which creates the > >> records. A list comprehension always creates a list. > > > > Well no. The list is created wi

Re: Enum with only a single member

2017-01-09 Thread Ethan Furman
On 01/09/2017 08:43 PM, Steven D'Aprano wrote: Is it silly to create an enumeration with only a single member? That is, a singleton enum? from enum import Enum class Unique(Enum): FOO = auto() The reason I ask is that I have two functions that take an enum argument. The first takes one

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Ethan Furman wrote, on January 09, 2017 8:01 PM > > On 01/09/2017 07:02 PM, Deborah Swanson wrote: > > Erik wrote, on January 09, 2017 5:47 PM > > >> As people keep saying, the object you have called 'records' is a > >> *list* of namedtuple objects. It is not a namedtuple. > >> > >> IIRC, you cr

Enum with only a single member

2017-01-09 Thread Steven D'Aprano
Is it silly to create an enumeration with only a single member? That is, a singleton enum? from enum import Enum class Unique(Enum): FOO = auto() The reason I ask is that I have two functions that take an enum argument. The first takes one of three enums: class MarxBros(Enum): GROUCH

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
MRAB wrote, on January 09, 2017 7:37 PM > > On 2017-01-10 03:02, Deborah Swanson wrote: > > Erik wrote, on January 09, 2017 5:47 PM > >> As people keep saying, the object you have called 'records' is a > >> *list* of namedtuple objects. It is not a namedtuple. > >> > >> IIRC, you create it using

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Erik
On 10/01/17 03:02, Deborah Swanson wrote: Erik wrote, on January 09, 2017 5:47 PM IIRC, you create it using a list comprehension which creates the records. A list comprehension always creates a list. Well no. The list is created with: records.extend(Record._make(row) for row in rows) No, th

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Ethan Furman
On 01/09/2017 07:02 PM, Deborah Swanson wrote: Erik wrote, on January 09, 2017 5:47 PM As people keep saying, the object you have called 'records' is a *list* of namedtuple objects. It is not a namedtuple. IIRC, you create it using a list comprehension which creates the records. A list compre

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread MRAB
On 2017-01-10 03:02, Deborah Swanson wrote: Erik wrote, on January 09, 2017 5:47 PM As people keep saying, the object you have called 'records' is a *list* of namedtuple objects. It is not a namedtuple. IIRC, you create it using a list comprehension which creates the records. A list comprehensi

Re: Clickable hyperlinks

2017-01-09 Thread Tim Chase
On 2017-01-09 14:33, Deborah Swanson wrote: > Ok, here is the crux of this thread's communication problem. I > didn't ask, or particularly care for all these lectures on the > technology of terminal emulators. I asked how to code Python to > make clickable links. The crux of the problem is that wo

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Erik wrote, on January 09, 2017 5:47 PM > As people keep saying, the object you have called 'records' > is a *list* > of namedtuple objects. It is not a namedtuple. > > IIRC, you create it using a list comprehension which creates the > records. A list comprehension always creates a list. Well

Re: Temporary variables in list comprehensions

2017-01-09 Thread Paul Rubin
Ben Bacarisse writes: > [(lambda tmp: (tmp, tmp+1))(expensive_calculation(x)) for x in data] Nice. The Haskell "let" expression is implemented as syntax sugar for that, I believe. -- https://mail.python.org/mailman/listinfo/python-list

Re: Temporary variables in list comprehensions

2017-01-09 Thread Tim Chase
On 2017-01-09 13:16, Paul Rubin wrote: > Tim Chase writes: > >> result = [(tmp, tmp+1) for tmp in map(expensive_calculation, > >> data)] > > > > As charmingly expressive as map() is, the wildly different > > behavior in py3 (it's a generator that evaluates lazily) vs py2 > > (it consumes the entir

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Erik
On 10/01/17 00:54, Deborah Swanson wrote: Since I won't change the order of the records again after the sort, I'm using records.sort(key=operator.attrgetter("Description", "Date")) once, which also works perfectly. So both sorted() and sort() can be used to sort namedtuples. Good to know! A

Re: Clickable hyperlinks

2017-01-09 Thread Joel Goldstick
On Mon, Jan 9, 2017 at 8:33 PM, Michael Torrie wrote: > On 01/09/2017 06:02 PM, Deborah Swanson wrote: >> Fair enough. I only suggested that they could have started their own >> thread, but mainly just to point out that they would have been off-topic >> if they did. I didn't demand that they do so

Announcing txAWS 0.2.3.1

2017-01-09 Thread Jean-Paul Calderone
I've just release txAWS 0.2.3.1. txAWS is a library for interacting with Amazon Web Services (AWS) using Twisted. AWSServiceEndpoint's ssl_hostname_verification's parameter now defaults to True instead of False. This affects all txAWS APIs which issue requests to AWS endpoints. For any applicat

Re: Clickable hyperlinks

2017-01-09 Thread Michael Torrie
On 01/09/2017 06:02 PM, Deborah Swanson wrote: > Fair enough. I only suggested that they could have started their own > thread, but mainly just to point out that they would have been off-topic > if they did. I didn't demand that they do so, I just wanted them to > think about it. I don't see how i

RE: Clickable hyperlinks

2017-01-09 Thread Deborah Swanson
Larry Martell wrote, on January 09, 2017 4:11 PM > > On Mon, Jan 9, 2017 at 5:33 PM, Deborah Swanson > wrote: > > Ok, here is the crux of this thread's communication problem. I didn't > > ask, or particularly care for all these lectures on the technology of > > terminal emulators. I asked how

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Peter Otten wrote, on January 09, 2017 3:27 PM > > While stable sort is nice in this case you can just say > > key=operator.attrgetter("Description", "Date") > > Personally I'd only use sorted() once and then switch to the > sort() method. This works perfectly, thank you. As I read the docs,

Re: Clickable hyperlinks

2017-01-09 Thread Larry Martell
On Mon, Jan 9, 2017 at 5:33 PM, Deborah Swanson wrote: > Ok, here is the crux of this thread's communication problem. I didn't > ask, or particularly care for all these lectures on the technology of > terminal emulators. I asked how to code Python to make clickable links. > > Since all of you are

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Peter Otten
breamore...@gmail.com wrote: > On Monday, January 9, 2017 at 5:34:12 PM UTC, Tim Chase wrote: >> On 2017-01-09 08:31, breamoreboy wrote: >> > On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote: >> > > I usually wrap the iterable in something like >> > > >> > > def pairwise(it): >> >

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread breamoreboy
On Monday, January 9, 2017 at 5:34:12 PM UTC, Tim Chase wrote: > On 2017-01-09 08:31, breamoreboy wrote: > > On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote: > > > I usually wrap the iterable in something like > > > > > > def pairwise(it): > > > prev = next(it) > > > for th

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Peter Otten
Rhodri James wrote: > On 09/01/17 21:40, Deborah Swanson wrote: >> Peter Otten wrote, on January 09, 2017 6:51 AM >>> >>> records = sorted( >>> set(records), >>> key=operator.attrgetter("Description") >>> ) >> >> Good, this is confirmation that 'sorted()' is the way to go. I want a 2 >> ke

Re: Temporary variables in list comprehensions

2017-01-09 Thread Ben Bacarisse
Steven D'Aprano writes: > Suppose you have an expensive calculation that gets used two or more times in > a > loop. The obvious way to avoid calculating it twice in an ordinary loop is > with > a temporary variable: > > result = [] > for x in data: > tmp = expensive_calculation(x) > r

RE: Clickable hyperlinks

2017-01-09 Thread Deborah Swanson
Tim Chase wrote, on January 09, 2017 5:53 AM > > On 2017-01-09 05:00, Deborah Swanson wrote: > > Code does in fact have the power to control what happens > > in the console. How do you think Linux does it on their terminals with > > clickable links? Granted, the code may have to specify parameter

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Rhodri James
On 09/01/17 21:40, Deborah Swanson wrote: Peter Otten wrote, on January 09, 2017 6:51 AM records = sorted( set(records), key=operator.attrgetter("Description") ) Good, this is confirmation that 'sorted()' is the way to go. I want a 2 key sort, Description and Date, but I think I can f

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
breamore...@gmail.com wrote, on January 09, 2017 8:32 AM > > On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote: > > On 2017-01-08 22:58, Deborah Swanson wrote: > > > 1) I have a section that loops through the sorted data, compares two > > > adjacent rows at a time, and marks one of th

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Tim Chase wrote, on January 09, 2017 6:22 AM > > On 2017-01-08 22:58, Deborah Swanson wrote: > > 1) I have a section that loops through the sorted data, compares two > > adjacent rows at a time, and marks one of them for deletion if the > > rows are identical. > > and my question is whether ther

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Peter Otten wrote, on January 09, 2017 6:51 AM > > Deborah Swanson wrote: > > > Even better, to get hold of all the records with the same Description > > as the current row, compare them all, mark all but the different ones > > for deletion, and then resume processing the records after the last

Re: Temporary variables in list comprehensions

2017-01-09 Thread Paul Rubin
Tim Chase writes: >> result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)] > > As charmingly expressive as map() is, the wildly different behavior in > py3 (it's a generator that evaluates lazily) vs py2 (it consumes the > entire iterable in one go) leads me to avoid it in general,

Re: [PSF-Community] Python Events in 2017, Need your help.

2017-01-09 Thread Danny Adair
Thanks Stephane, Kiwi PyCon 2017 will be in Auckland, New Zealand in September - exact dates and location not yet determined. I'll submit it when they are. Cheers, Danny On Mon, Jan 9, 2017 at 10:54 PM, Stephane Wirtel via PSF-Community wrote: > Dear Community, > > For the PythonFOSDEM [1] on

RE: Help with this code

2017-01-09 Thread Joaquin Alzola
>> elements. For example, if we have a list_a=["a","b","c","d"] and >> list_b=["a","b"] I want to obtain a new list_c containing elements that >> match between these lists (a and b here), >Perhaps this might work: list(set(list_a).intersection(set(list_b))) >['a', 'b'] >>> list_a={"a","b","

Re: Temporary variables in list comprehensions

2017-01-09 Thread Christian Gollwitzer
Am 09.01.17 um 04:53 schrieb Steven D'Aprano: Or do you? ... no, you don't! [(tmp, tmp + 1) for x in data for tmp in [expensive_calculation(x)]] I can't decide whether that's an awesome trick or a horrible hack... I think this is quite clear, and a useful feature, only that Python makes it u

Re: Temporary variables in list comprehensions

2017-01-09 Thread Antonio Caminero Garcia
On Sunday, January 8, 2017 at 7:53:37 PM UTC-8, Steven D'Aprano wrote: > Suppose you have an expensive calculation that gets used two or more times in > a > loop. The obvious way to avoid calculating it twice in an ordinary loop is > with > a temporary variable: > > result = [] > for x in data

Re: Clickable hyperlinks

2017-01-09 Thread Michael Torrie
On 01/09/2017 10:27 AM, Michael Torrie wrote: >> You can use tkinter (code >> in a program) to make clickable links in the console, > > Unless you're talking about an implementation of a console or terminal > emulator in tkinter, this is incorrect. Tkinter does not do anything > with standard ou

Re: Help with this code

2017-01-09 Thread Joel Goldstick
On Mon, Jan 9, 2017 at 1:02 PM, Gilmeh Serda wrote: > On Mon, 09 Jan 2017 05:08:51 -0800, José Manuel Suárez Sierra wrote: > >> elements. For example, if we have a list_a=["a","b","c","d"] and >> list_b=["a","b"] I want to obtain a new list_c containing elements that >> match between these lists (

Re: Search a sequence for its minimum and stop as soon as the lowest possible value is found

2017-01-09 Thread Peter Otten
Antonio Caminero Garcia wrote: > On Friday, January 6, 2017 at 6:04:33 AM UTC-8, Peter Otten wrote: >> Example: you are looking for the minimum absolute value in a series of >> integers. As soon as you encounter the first 0 it's unnecessary extra >> work to check the remaining values, but the buil

Re: Clickable hyperlinks

2017-01-09 Thread Michael Torrie
On 01/09/2017 06:00 AM, Deborah Swanson wrote: > Rhodri James wrote, on January 09, 2017 4:28 AM >> >> Nope. PyCharm outputs text to the console that the console >> chooses to >> interpret as a link and makes clickable. As Stephen pointed >> out right >> back at the beginning of this thread,

Re: Temporary variables in list comprehensions

2017-01-09 Thread Tim Chase
On 2017-01-09 04:59, Rustom Mody wrote: > What happens when the expensive is on an inner generator? > Something like: > > [expensive₂(y) for x in data for y in foo(x)] > > [The ₂ representing the 2 or more occurrences in Steven's eg] Well, if I understand your question correctly, the goal would

Re: Error message IDLE

2017-01-09 Thread Gretchen Hasselbring
Thank you for your responses. The file I think is responsible was called types.py Sent from my iPad > On 9 Jan 2017, at 16:11, Peter Otten <__pete...@web.de> wrote: > > Gretchen Hasselbring wrote: > >> FYI >> >> Turns out I was saving my practice exercises as files (.py) under the >> pyt

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread breamoreboy
On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote: > On 2017-01-08 22:58, Deborah Swanson wrote: > > 1) I have a section that loops through the sorted data, compares two > > adjacent rows at a time, and marks one of them for deletion if the > > rows are identical. > > > > I'm using >

enable-framework Vs. Naught

2017-01-09 Thread André Lemos
Hi, I have a C++ module that I am compiling to use inside of my Python installation under Mac OS. If I compile & link it against a Framework enabled Python installation, it works fine, but if I compile & link it against a *non* enabled Framework installation that we use for distribution, I simpl

Re: Error message IDLE

2017-01-09 Thread Peter Otten
Gretchen Hasselbring wrote: > FYI > > Turns out I was saving my practice exercises as files (.py) under the > python directory which conflicted with the running of Idle. All cleared > up now. Thanks for the update. Can you tell which file you shadowed to cause the error? Perhaps even if the un

Re: Help with this code

2017-01-09 Thread Peter Otten
José Manuel Suárez Sierra wrote: > This is the traceback: > line 18, in > for transf2[j] in transf2: > IndexError: list assignment index out of range > > If I have initialized j=0 (such as i) why does it not work? A for loop for x in y: ... sequentually assigns every value in y to x. So wi

Re: Error message IDLE

2017-01-09 Thread Terry Reedy
On 1/9/2017 6:48 AM, Gretchen Hasselbring wrote: Hello Trying to learn python on a laptop. Was successful for awhile then... Had a 'subprocess startup error' 'IDLE's subprocess didn't make connection. Either IDLE can't start subprocess or personal firewall software is blocking the connectio

Re: Error message IDLE

2017-01-09 Thread Gretchen Hasselbring
FYI Turns out I was saving my practice exercises as files (.py) under the python directory which conflicted with the running of Idle. All cleared up now. Sent from my iPad > On 9 Jan 2017, at 12:16, Gretchen Hasselbring > wrote: > > Hello > > Trying to learn python on a laptop. Was succes

Re: Clickable hyperlinks

2017-01-09 Thread Rhodri James
On 09/01/17 13:53, Tim Chase wrote: On 2017-01-09 05:00, Deborah Swanson wrote: The console is a dead thing, it has no mind or soul to choose anything. Surely an educated person would know that. Pretty much every quality system administrator I know uses the terminal. Just about all of the bes

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Peter Otten
Deborah Swanson wrote: > Even better, to get hold of all the records with the same Description as > the current row, compare them all, mark all but the different ones for > deletion, and then resume processing the records after the last one? When you look at all fields for deduplication anyway th

Re: Help with this code

2017-01-09 Thread José Manuel Suárez Sierra
El lunes, 9 de enero de 2017, 14:09:09 (UTC+1), José Manuel Suárez Sierra escribió: > Hello, I am trying to make a code wich compares between 2 or several > sequences (lists). It compares every element in a list with another list > elements. For example, if we have a list_a=["a","b","c","d"] an

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Tim Chase
On 2017-01-08 22:58, Deborah Swanson wrote: > 1) I have a section that loops through the sorted data, compares two > adjacent rows at a time, and marks one of them for deletion if the > rows are identical. > > I'm using > > for i in range(len(records)-1): > r1 = records[i] > r2 = records

Re: Clickable hyperlinks

2017-01-09 Thread Tim Chase
On 2017-01-09 05:00, Deborah Swanson wrote: > Code does in fact have the power to control what happens > in the console. How do you think Linux does it on their terminals > with clickable links? Granted, the code may have to specify > parameters for a particular console, but I certainly wasn't aski

Re: Help with this code

2017-01-09 Thread José Manuel Suárez Sierra
El lunes, 9 de enero de 2017, 14:09:09 (UTC+1), José Manuel Suárez Sierra escribió: > Hello, I am trying to make a code wich compares between 2 or several > sequences (lists). It compares every element in a list with another list > elements. For example, if we have a list_a=["a","b","c","d"] an

Re: Help with this code

2017-01-09 Thread Peter Otten
José Manuel Suárez Sierra wrote: > Hello, Welcome! > I am trying to make a code wich compares between 2 or several > sequences (lists). It compares every element in a list with another list > elements. For example, if we have a list_a=["a","b","c","d"] and > list_b=["a","b"] I want to obtain a

RE: Help with this code

2017-01-09 Thread Deborah Swanson
José Manuel Suárez Sierra wrote, on January 09, 2017 5:09 AM > > Hello, I am trying to make a code wich compares between 2 or > several sequences (lists). It compares every element in a > list with another list elements. For example, if we have a > list_a=["a","b","c","d"] and list_b=["a","b"]

Re: Temporary variables in list comprehensions

2017-01-09 Thread Antoon Pardon
Op 09-01-17 om 04:53 schreef Steven D'Aprano: > Suppose you have an expensive calculation that gets used two or more times in > a > loop. The obvious way to avoid calculating it twice in an ordinary loop is > with > a temporary variable: > > result = [] > for x in data: > tmp = expensive_ca

Help with this code

2017-01-09 Thread José Manuel Suárez Sierra
Hello, I am trying to make a code wich compares between 2 or several sequences (lists). It compares every element in a list with another list elements. For example, if we have a list_a=["a","b","c","d"] and list_b=["a","b"] I want to obtain a new list_c containing elements that match between the

Re: Temporary variables in list comprehensions

2017-01-09 Thread Rustom Mody
On Monday, January 9, 2017 at 5:54:15 PM UTC+5:30, Tim Chase wrote: > On 2017-01-09 02:46, Paul Rubin wrote: > > > gen = (expensive_calculation(x) for x in data) > > > result = [(tmp, tmp + 1) for tmp in gen] > > > > result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)] > > As cha

RE: Clickable hyperlinks

2017-01-09 Thread Deborah Swanson
Rhodri James wrote, on January 09, 2017 4:28 AM > > Nope. PyCharm outputs text to the console that the console > chooses to > interpret as a link and makes clickable. As Stephen pointed > out right > back at the beginning of this thread, printing the textual > string that > is a URL could

Re: Clickable hyperlinks

2017-01-09 Thread Rhodri James
On 05/01/17 02:53, Deborah Swanson (Deborah Swanson) wrote: Rhodri James wrote, on January 05, 2017 3:53 AM On 05/01/17 04:52, Deborah Swanson wrote: My original question was in fact whether there was a way to make clickable hyperlinks in a console. I was persuaded after about 10 replies that

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Steve D'Aprano wrote, on January 09, 2017 3:40 AM > > On Mon, 9 Jan 2017 09:57 pm, Deborah Swanson wrote: > > [...] > > I think you are replying to my question about sorting a > namedtuple, in > > this case it's called 'records'. > > > > I think your suggestion works for lists and tuples, and

Re: Temporary variables in list comprehensions

2017-01-09 Thread Tim Chase
On 2017-01-09 02:46, Paul Rubin wrote: > > gen = (expensive_calculation(x) for x in data) > > result = [(tmp, tmp + 1) for tmp in gen] > > result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)] As charmingly expressive as map() is, the wildly different behavior in py3 (it's a gener

Error message IDLE

2017-01-09 Thread Gretchen Hasselbring
Hello Trying to learn python on a laptop. Was successful for awhile then... Had a 'subprocess startup error' 'IDLE's subprocess didn't make connection. Either IDLE can't start subprocess or personal firewall software is blocking the connection ' Doesn't appear to be firewall and I uninstall

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Steve D'Aprano
On Mon, 9 Jan 2017 09:57 pm, Deborah Swanson wrote: [...] > I think you are replying to my question about sorting a namedtuple, in > this case it's called 'records'. > > I think your suggestion works for lists and tuples, and probably > dictionaries. But namedtuples doesn't have a sort function.

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Antoon Pardon wrote, on January 09, 2017 2:35 AM > If I understand correctly you want something like: > > records.sort(key = lamda rec: rec.xx) > > AKA > > from operator import attrgetter > records.sort(key = attrgetter('xx')) > > or maybe: > > records.sort(key = lambda rec:

Re: Temporary variables in list comprehensions

2017-01-09 Thread Paul Rubin
Serhiy Storchaka writes: > gen = (expensive_calculation(x) for x in data) > result = [(tmp, tmp + 1) for tmp in gen] result = [(tmp, tmp+1) for tmp in map(expensive_calculation, data)] -- https://mail.python.org/mailman/listinfo/python-list

Re: Temporary variables in list comprehensions

2017-01-09 Thread Paul Rubin
Steven D'Aprano writes: > [(expensive_calculation(x), expensive_calculation(x) + 1) for x in data] def memoize(f): cache = {} def m(x): if x in cache: return cache[x] a = f(x) cache[x] = a r

RE: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Deborah Swanson
Antoon Pardon wrote, on January 09, 2017 2:14 AM > > 1) I have a section that loops through the sorted data, compares two > > adjacent rows at a time, and marks one of them for deletion if the > > rows are identical. > > > > I'm using > > > > for i in range(len(records)-1): > > r1 = records[

Re: Temporary variables in list comprehensions

2017-01-09 Thread Serhiy Storchaka
On 09.01.17 05:53, Steven D'Aprano wrote: Suppose you have an expensive calculation that gets used two or more times in a loop. The obvious way to avoid calculating it twice in an ordinary loop is with a temporary variable: result = [] for x in data: tmp = expensive_calculation(x) result

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Antoon Pardon
Op 09-01-17 om 07:58 schreef Deborah Swanson: > Peter Otten wrote, on January 08, 2017 5:21 AM >> Deborah Swanson wrote: >> >>> Peter Otten wrote, on January 08, 2017 3:01 AM >> >> Personally I would recommend against mixing data (an actual location) > and >> metadata (the column name,"Location"

Re: Using namedtuples field names for column indices in a list of lists

2017-01-09 Thread Antoon Pardon
Op 09-01-17 om 07:58 schreef Deborah Swanson: > Peter Otten wrote, on January 08, 2017 5:21 AM >> Deborah Swanson wrote: >> >>> Peter Otten wrote, on January 08, 2017 3:01 AM >> >> Personally I would recommend against mixing data (an actual location) > and >> metadata (the column name,"Location"

Python Events in 2017, Need your help.

2017-01-09 Thread Stephane Wirtel via Python-list
Dear Community, For the PythonFOSDEM [1] on 4th and 5th February in Belgium, I would like to present some slides with the Python events around the World. Based on https://python.org/events, I have noted that there are missing events, for example: * PyCon Otto: Italy * PyCon UK: United Kingd