Strongness of Python == vs in operator [duplicate]










3
















This question already has an answer here:



  • Why does `True == False is False` evaluate to False? [duplicate]

    4 answers



  • Python comparison operators chaining/grouping left to right?

    1 answer



  • Python chained comparison

    4 answers



I'm stumbling a bit why the following code



str1 = "text"
str2 = "some longer text"
if str1 in str2 == True:
 pass # do something


is not working. (I know that I can easily fix this problem by writing if str1 in str2 == True: - this is not the question!)



The question is, why is



str1 in str2 == True


returning False? I mean if the operator in is stronger than the == operator, I would have the following code



if (str1 in str2) == True:


which is actually working (as it will be evaluated to True) ... And if it is the other way round, that the == operator is stronger than the inoperator, I would expect an TypeError: argument of type 'bool' is not iterable Exception. Actually the code



if a = "" in ("" == True):


is raising such an exception. So what is Python doing here? Which operator (in vs ==) is evaluated first? And why is the result False:



a = ("" in "" == True)


and not True or an TypeError: argument of type 'bool' is not iterableException? The only way I could imagine theFalse` result is that Python is trying to execute both operators all together. But how is it working then?



Things I noticed:



  • Python2 and Python3 are both showing the same result.

  • The statement "" in "" == "" is actually returning True

  • If you have the code a = ("" in "" == True), type(a) will result in <type 'bool'>. So the result is actually a boolean - as expected - and not some kind of other object. Nevertheless print(a) results False.





python python-3.x python-2.7







share|improve this question















marked as duplicate by deceze♦ python
Users with the  python badge can single-handedly close python questions as duplicates and reopen them as needed.

StackExchange.ready(function()
if (StackExchange.options.isMobile) return;

$('.dupe-hammer-message-hover:not(.hover-bound)').each(function()
var $hover = $(this).addClass('hover-bound'),
$msg = $hover.siblings('.dupe-hammer-message');

$hover.hover(
function()
$hover.showInfoMessage('',
messageElement: $msg.clone().show(),
transient: false,
position: my: 'bottom left', at: 'top center', offsetTop: -7 ,
dismissable: false,
relativeToBody: true
);
,
function()
StackExchange.helpers.removeMessages();

);
);
);
 Nov 13 '18 at 8:09


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.















  • There is absolutely no reason to ever write == True (*except for very specific circumstances). Just do if str1 in str2:. What you're creating there is a chained comparison.

    – deceze♦
    Nov 13 '18 at 8:10












  • @deceze I know that there is no reason to ever write == True. I just wanted to know what is happening when you do it nevertheless. And neither stackoverflow.com/questions/25753474/… nor stackoverflow.com/questions/24018315/python-chained-comparison is a duplicate. As explained in my question - when these operators would be chained, then the code str1 in str2 == Truewould either equal to str1 in (str2 == True) or (str1 in str2) == True however this is not the case.

    – quant
    Nov 13 '18 at 8:16






  • 4





    Err, no, then you don't quite understand what a chain is yet. See stackoverflow.com/a/25753528/476 again. What you have is equivalent to (str1 in str2) and (str2 == True)!

    – deceze♦
    Nov 13 '18 at 8:19
















3
















This question already has an answer here:



  • Why does `True == False is False` evaluate to False? [duplicate]

    4 answers



  • Python comparison operators chaining/grouping left to right?

    1 answer



  • Python chained comparison

    4 answers



I'm stumbling a bit why the following code



str1 = "text"
str2 = "some longer text"
if str1 in str2 == True:
 pass # do something


is not working. (I know that I can easily fix this problem by writing if str1 in str2 == True: - this is not the question!)



The question is, why is



str1 in str2 == True


returning False? I mean if the operator in is stronger than the == operator, I would have the following code



if (str1 in str2) == True:


which is actually working (as it will be evaluated to True) ... And if it is the other way round, that the == operator is stronger than the inoperator, I would expect an TypeError: argument of type 'bool' is not iterable Exception. Actually the code



if a = "" in ("" == True):


is raising such an exception. So what is Python doing here? Which operator (in vs ==) is evaluated first? And why is the result False:



a = ("" in "" == True)


and not True or an TypeError: argument of type 'bool' is not iterableException? The only way I could imagine theFalse` result is that Python is trying to execute both operators all together. But how is it working then?



Things I noticed:



  • Python2 and Python3 are both showing the same result.

  • The statement "" in "" == "" is actually returning True

  • If you have the code a = ("" in "" == True), type(a) will result in <type 'bool'>. So the result is actually a boolean - as expected - and not some kind of other object. Nevertheless print(a) results False.





python python-3.x python-2.7







share|improve this question















marked as duplicate by deceze♦ python
Users with the  python badge can single-handedly close python questions as duplicates and reopen them as needed.

StackExchange.ready(function()
if (StackExchange.options.isMobile) return;

$('.dupe-hammer-message-hover:not(.hover-bound)').each(function()
var $hover = $(this).addClass('hover-bound'),
$msg = $hover.siblings('.dupe-hammer-message');

$hover.hover(
function()
$hover.showInfoMessage('',
messageElement: $msg.clone().show(),
transient: false,
position: my: 'bottom left', at: 'top center', offsetTop: -7 ,
dismissable: false,
relativeToBody: true
);
,
function()
StackExchange.helpers.removeMessages();

);
);
);
 Nov 13 '18 at 8:09


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.















  • There is absolutely no reason to ever write == True (*except for very specific circumstances). Just do if str1 in str2:. What you're creating there is a chained comparison.

    – deceze♦
    Nov 13 '18 at 8:10












  • @deceze I know that there is no reason to ever write == True. I just wanted to know what is happening when you do it nevertheless. And neither stackoverflow.com/questions/25753474/… nor stackoverflow.com/questions/24018315/python-chained-comparison is a duplicate. As explained in my question - when these operators would be chained, then the code str1 in str2 == Truewould either equal to str1 in (str2 == True) or (str1 in str2) == True however this is not the case.

    – quant
    Nov 13 '18 at 8:16






  • 4





    Err, no, then you don't quite understand what a chain is yet. See stackoverflow.com/a/25753528/476 again. What you have is equivalent to (str1 in str2) and (str2 == True)!

    – deceze♦
    Nov 13 '18 at 8:19














3












3








3









This question already has an answer here:



  • Why does `True == False is False` evaluate to False? [duplicate]

    4 answers



  • Python comparison operators chaining/grouping left to right?

    1 answer



  • Python chained comparison

    4 answers



I'm stumbling a bit why the following code



str1 = "text"
str2 = "some longer text"
if str1 in str2 == True:
 pass # do something


is not working. (I know that I can easily fix this problem by writing if str1 in str2 == True: - this is not the question!)



The question is, why is



str1 in str2 == True


returning False? I mean if the operator in is stronger than the == operator, I would have the following code



if (str1 in str2) == True:


which is actually working (as it will be evaluated to True) ... And if it is the other way round, that the == operator is stronger than the inoperator, I would expect an TypeError: argument of type 'bool' is not iterable Exception. Actually the code



if a = "" in ("" == True):


is raising such an exception. So what is Python doing here? Which operator (in vs ==) is evaluated first? And why is the result False:



a = ("" in "" == True)


and not True or an TypeError: argument of type 'bool' is not iterableException? The only way I could imagine theFalse` result is that Python is trying to execute both operators all together. But how is it working then?



Things I noticed:



  • Python2 and Python3 are both showing the same result.

  • The statement "" in "" == "" is actually returning True

  • If you have the code a = ("" in "" == True), type(a) will result in <type 'bool'>. So the result is actually a boolean - as expected - and not some kind of other object. Nevertheless print(a) results False.





python python-3.x python-2.7







share|improve this question

















This question already has an answer here:



  • Why does `True == False is False` evaluate to False? [duplicate]

    4 answers



  • Python comparison operators chaining/grouping left to right?

    1 answer



  • Python chained comparison

    4 answers



I'm stumbling a bit why the following code



str1 = "text"
str2 = "some longer text"
if str1 in str2 == True:
 pass # do something


is not working. (I know that I can easily fix this problem by writing if str1 in str2 == True: - this is not the question!)



The question is, why is



str1 in str2 == True


returning False? I mean if the operator in is stronger than the == operator, I would have the following code



if (str1 in str2) == True:


which is actually working (as it will be evaluated to True) ... And if it is the other way round, that the == operator is stronger than the inoperator, I would expect an TypeError: argument of type 'bool' is not iterable Exception. Actually the code



if a = "" in ("" == True):


is raising such an exception. So what is Python doing here? Which operator (in vs ==) is evaluated first? And why is the result False:



a = ("" in "" == True)


and not True or an TypeError: argument of type 'bool' is not iterableException? The only way I could imagine theFalse` result is that Python is trying to execute both operators all together. But how is it working then?



Things I noticed:



  • Python2 and Python3 are both showing the same result.

  • The statement "" in "" == "" is actually returning True

  • If you have the code a = ("" in "" == True), type(a) will result in <type 'bool'>. So the result is actually a boolean - as expected - and not some kind of other object. Nevertheless print(a) results False.




This question already has an answer here:



  • Why does `True == False is False` evaluate to False? [duplicate]

    4 answers



  • Python comparison operators chaining/grouping left to right?

    1 answer



  • Python chained comparison

    4 answers






python python-3.x python-2.7




python python-3.x python-2.7






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 13 '18 at 8:23







quant

















asked Nov 13 '18 at 8:06









quantquant

1,58211526




1,58211526




marked as duplicate by deceze♦ python
Users with the  python badge can single-handedly close python questions as duplicates and reopen them as needed.

StackExchange.ready(function()
if (StackExchange.options.isMobile) return;

$('.dupe-hammer-message-hover:not(.hover-bound)').each(function()
var $hover = $(this).addClass('hover-bound'),
$msg = $hover.siblings('.dupe-hammer-message');

$hover.hover(
function()
$hover.showInfoMessage('',
messageElement: $msg.clone().show(),
transient: false,
position: my: 'bottom left', at: 'top center', offsetTop: -7 ,
dismissable: false,
relativeToBody: true
);
,
function()
StackExchange.helpers.removeMessages();

);
);
);
 Nov 13 '18 at 8:09


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.






marked as duplicate by deceze♦ python
Users with the  python badge can single-handedly close python questions as duplicates and reopen them as needed.

StackExchange.ready(function()
if (StackExchange.options.isMobile) return;

$('.dupe-hammer-message-hover:not(.hover-bound)').each(function()
var $hover = $(this).addClass('hover-bound'),
$msg = $hover.siblings('.dupe-hammer-message');

$hover.hover(
function()
$hover.showInfoMessage('',
messageElement: $msg.clone().show(),
transient: false,
position: my: 'bottom left', at: 'top center', offsetTop: -7 ,
dismissable: false,
relativeToBody: true
);
,
function()
StackExchange.helpers.removeMessages();

);
);
);
 Nov 13 '18 at 8:09


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.














  • There is absolutely no reason to ever write == True (*except for very specific circumstances). Just do if str1 in str2:. What you're creating there is a chained comparison.

    – deceze♦
    Nov 13 '18 at 8:10












  • @deceze I know that there is no reason to ever write == True. I just wanted to know what is happening when you do it nevertheless. And neither stackoverflow.com/questions/25753474/… nor stackoverflow.com/questions/24018315/python-chained-comparison is a duplicate. As explained in my question - when these operators would be chained, then the code str1 in str2 == Truewould either equal to str1 in (str2 == True) or (str1 in str2) == True however this is not the case.

    – quant
    Nov 13 '18 at 8:16






  • 4





    Err, no, then you don't quite understand what a chain is yet. See stackoverflow.com/a/25753528/476 again. What you have is equivalent to (str1 in str2) and (str2 == True)!

    – deceze♦
    Nov 13 '18 at 8:19


















  • There is absolutely no reason to ever write == True (*except for very specific circumstances). Just do if str1 in str2:. What you're creating there is a chained comparison.

    – deceze♦
    Nov 13 '18 at 8:10












  • @deceze I know that there is no reason to ever write == True. I just wanted to know what is happening when you do it nevertheless. And neither stackoverflow.com/questions/25753474/… nor stackoverflow.com/questions/24018315/python-chained-comparison is a duplicate. As explained in my question - when these operators would be chained, then the code str1 in str2 == Truewould either equal to str1 in (str2 == True) or (str1 in str2) == True however this is not the case.

    – quant
    Nov 13 '18 at 8:16






  • 4





    Err, no, then you don't quite understand what a chain is yet. See stackoverflow.com/a/25753528/476 again. What you have is equivalent to (str1 in str2) and (str2 == True)!

    – deceze♦
    Nov 13 '18 at 8:19

















There is absolutely no reason to ever write == True (*except for very specific circumstances). Just do if str1 in str2:. What you're creating there is a chained comparison.

– deceze♦
Nov 13 '18 at 8:10






There is absolutely no reason to ever write == True (*except for very specific circumstances). Just do if str1 in str2:. What you're creating there is a chained comparison.

– deceze♦
Nov 13 '18 at 8:10














@deceze I know that there is no reason to ever write == True. I just wanted to know what is happening when you do it nevertheless. And neither stackoverflow.com/questions/25753474/… nor stackoverflow.com/questions/24018315/python-chained-comparison is a duplicate. As explained in my question - when these operators would be chained, then the code str1 in str2 == Truewould either equal to str1 in (str2 == True) or (str1 in str2) == True however this is not the case.

– quant
Nov 13 '18 at 8:16





@deceze I know that there is no reason to ever write == True. I just wanted to know what is happening when you do it nevertheless. And neither stackoverflow.com/questions/25753474/… nor stackoverflow.com/questions/24018315/python-chained-comparison is a duplicate. As explained in my question - when these operators would be chained, then the code str1 in str2 == Truewould either equal to str1 in (str2 == True) or (str1 in str2) == True however this is not the case.

– quant
Nov 13 '18 at 8:16




4




4





Err, no, then you don't quite understand what a chain is yet. See stackoverflow.com/a/25753528/476 again. What you have is equivalent to (str1 in str2) and (str2 == True)!

– deceze♦
Nov 13 '18 at 8:19






Err, no, then you don't quite understand what a chain is yet. See stackoverflow.com/a/25753528/476 again. What you have is equivalent to (str1 in str2) and (str2 == True)!

– deceze♦
Nov 13 '18 at 8:19













0






active

oldest

votes

















0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes

-

這個網誌中的熱門文章

How to read a connectionString WITH PROVIDER in .NET Core?

圖片
6 I added .AddJsonFile("Connections.json", optional: true, reloadOnChange: true) in public Startup(IHostingEnvironment env) Connections.json contains: "ConnectionStrings": "DefaultConnection": "Server=(localdb)\mssqllocaldb;Database=DATABASE;Trusted_Connection=True;MultipleActiveResultSets=true", "COR-W81-101": "Data Source=DATASOURCE;Initial Catalog=P61_CAFM_Basic;User Id=USERID;Password=PASSWORD;Persist Security Info=False;MultipleActiveResultSets=False;Packet Size=4096;", "COR-W81-100": "Data Source=DATASOURCE;Initial Catalog=Post_PS;User Id=USERID;Password=PASSWORD;Persist Security Info=False;MultipleActiveResultSets=False;Packet Size=4096;", "MSEDGEWIN10": "Data Source=DATASOURCE; Initial Catalog=COR_Basic; Persist Security Info=False;Integrated Security=true;MultipleActiveResultSets=False;Packet Size=4096;Application Name="COR_Basic"", "server&qu
閱讀完整內容

In R, how to develop a multiplot heatmap.2 figure showing key labels successfully

圖片
1 2 I'm trying to develop a multiplot heatmap.2 saved to a pdf. I'm having some success but the axis labels are getting chopped off. Subplot titles are also desirable but again the labels are getting chopped. Here's my reproducible code: library(gridExtra) library(grid) library(gridGraphics) library(gplots) Col = colorRampPalette(c("red","orange","yellow", "white")) grab_grob <- function() grid.echo() grid.grab() par(cex.main=0.1, mar = c(1,1,1,1) ) #data<-read.table("heatmap.input.matrix.data.txt") lmat = rbind(c(2,3),c(4,1),c(4,1)) lwid = c(2.5,4) lhei = c(0.5,4,3) labRowvec <- c(rep(NULL, dim(matrix(runif(1000, 1,10),ncol=50))[1])) labColvec <- c(rep(NULL, dim(matrix(runif(1000, 1,10),ncol=50))[2])) gl <- lapply(1:12, function(i) heatmap.2(matrix(runif(1000, 1,10),ncol=50), dendrogram = "none",offsetRow=-0.5, offsetCol=-1,srtCol=0, density="density", lmat =lmat,lhei = l
閱讀完整內容

Museum of Modern and Contemporary Art of Trento and Rovereto

圖片
Art museum in Rovereto TN, Italy Museum of Modern and Contemporary Art of Trento and Rovereto Museo d'arte moderna e contemporanea di Trento e Rovereto MART, Entrance Location Corso Angelo Bettini, 43, 38068 Rovereto TN, Italy Coordinates 45°53′38″N 11°02′42″E  /  45.8940°N 11.0450°E  / 45.8940; 11.0450 Coordinates: 45°53′38″N 11°02′42″E  /  45.8940°N 11.0450°E  / 45.8940; 11.0450 Type Art museum Director Gianfranco Maraniello Public transit access Trento train station. Taxis outside station. Website mart.trento.it The Museum of Modern and Contemporary Art of Trento and Rovereto (MART) ( Museo d'Arte Moderna e Contemporanea di Trento e Rovereto , in Italian) is a museum centre in the Italian province of Trento. The main site is in Rovereto, and contains mostly modern and contemporary artworks, including works from renowned Giorgio Morandi, Giorgio de Chirico, Felice Casorati, Carlo Carrà and Fortunato Depero. Fortunato Depero's house in Rovereto (known as Casa d
閱讀完整內容