Re: [Tutor] Test for type(object) == ???
On Sat, Feb 11, 2017 at 7:35 AM, boB Stepp wrote: > Has this PEP been implemented yet? I am running Python 3.5.2 and it > appears not to work. Also, in "What's New In Python 3.6" > (https://docs.python.org/3/whatsnew/3.6.html) I did not see a mention > of it. You can see in the document header that PEP 457 is an Informational document at the draft stage, as opposed to a Standards Track document that's finalized. It's the best I could find as provisional documentation of CPython's usage of '/' to mark positional-only arguments of built-in functions. FYI, the PEP's author, Larry Hastings, is also the author of Argument Clinic. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Python-list thread: int vs. float
On Fri, Feb 10, 2017 at 07:59:04PM -0600, boB Stepp wrote:
> He cannot figure out how to reliably tell if the user's input is an
> integer, float or neither. So I thought I would come up with my
> solution, which currently is:
>
> py3: def ck_input():
> ... value_to_ck = input('Enter a number:')
> ... try:
> ... value = int(value_to_ck)
> ... print('You have entered an integer.')
> ... except ValueError:
> ... try:
> ... value = float(value_to_ck)
> ... print('You have entered a float.')
> ... except ValueError:
> ... print('You have failed to enter a numerical value.')
> ...
[...]
> This is all well and good. I am not trying to elicit an "Atta boy,
> boB!" here. ~(:>))
Nevertheless, atta boy boB!
The only not-so-good part of this is that you have mixed user-interface
and internal calculation. Better:
def to_number(string):
"""Convert string to either an int or a float, or raise ValueError."""
try:
return int(string)
except ValueError:
return float(string)
def check_input():
value_to_ck = input('Enter a number: ')
try:
value = to_number(value_to_ck)
except ValueError:
print('You have failed to enter a numerical value.')
return
if isinstance(value, float):
print('You have entered a float.')
else:
print('You have entered an int.')
This gives you nice separation between the function that interacts with
the user, and the function that does the actual conversion.
> Instead, I am wondering if there is something in
> Python's wonderful cornucopia of programming stuff that can simplify
> this type of check.
The most reliable and foolproof way of checking if something is a valid
int is to ask int to convert it, and see if it fails.
Likewise for floats, where the format is *very* complex. Any of these,
and many more, should be accepted:
1.2345
+1.2345
-1.2345e0
123.45e+20
123.45E-20
.123
-.123
+.123e-12
123.
inf
+inf
-inf
NaN
Getting all the gory details right of what is and isn't allowed may be
tricky, but that's okay, because float() already understands how to do
it for you.
> As you might guess from my earlier post this
> evening, I have been playing around with "type()" and "isinstance()",
> but if I try something like:
>
> py3: isinstance(int('5.0'))
> Traceback (most recent call last):
> File "", line 1, in
> ValueError: invalid literal for int() with base 10: '5.0'
The problem here is that int('5.0') raises an exception because '.' is
not a valid digit for integers, so it fails before isinstance() gets a
chance to run.
Valid digits for integers include 0 through 9 in decimal, plus no more
than one leading + or - sign, and whitespace (space, tabs, newlines)
before or after the string. If you specify the base, the set of valid
digits will change, e.g. int(string, 16) will allow 0 through 9 plus A
through F in lower and upper case.
But whatever base you choose, '.' is not a valid digit.
--
Steve
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Re: [Tutor] Python-list thread: int vs. float
On Sat, Feb 11, 2017 at 8:06 AM, Steven D'Aprano wrote: > Valid digits for integers include 0 through 9 in decimal Note that Python 3 uses the Unicode database to determine the decimal value of characters, if any. It's not limited to the ASCII decimal digits 0-9. For example: >>> s '௧꘢୩' >>> int(s) 123 >>> print(*(unicodedata.name(c) for c in s), sep='\n') TAMIL DIGIT ONE VAI DIGIT TWO ORIYA DIGIT THREE ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Test for type(object) == ???
On Fri, Feb 10, 2017 at 07:34:35PM -0600, boB Stepp wrote: > I was playing around with type() tonight. If I type (pun intended), I get: > > py3: type(5) > > > So I naively thought a test for type int should go like: > > py3: type(5) == "" > False The interactive intepreter is great, but you have to remember that what you see is not necessarily what you've got. What you *see* is the string representation of the object: py> print but what you've actually got is the object itself; in this case, it is the print function, and in your case, it is the int class. Generally angle brackets < > mean that the text between the brackets is just a display form, something intended for the human reader, and not a programmable syntax. You then have to know (from experience) how to refer to the object in code. In the case of int, there are three distinct things here: - the class (or type) itself, a blob of memory somewhere in the interpreter containing various methods and attributes used for working with integers; - the name the interpreter knows that class by, namely "int"; - the string representation for the human reader, "". So long as you remember the difference between the object itself, the name we use to talk about the object, and the way we visually display the object, you can't go wrong :-) (The nation Russia is not the same as a map of Russia, which is not the same as the word Russia, which is not the same as the letters R u s s i a, or even Р о с с и ́я for that matter). As they say: the map is not the territory. Or in the words of Steven Wright, "I have a map of the United States... Actual size. It says, 'Scale: 1 mile = 1 mile.' I spent last summer folding it." > I finally stumbled onto the correct form: > > py3: type(5) == int > True type(5) returns the class that we call "int". The name "int" returns that same class. > So my question is why does "type(5)" result in "", No, that's just the string representation of int. Inside the interactive interpreter, when you hit ENTER, the interpreter evaluates the line of code you have, generates a result, and then does the equivalent of: print(repr(result)) (except that None is suppressed). -- Steve ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Test for type(object) == ???
On Sat, Feb 11, 2017 at 01:00:11PM +1100, Ben Finney wrote: > boB Stepp writes: > > > I was playing around with type() tonight. If I type (pun intended), I get: > > > > py3: type(5) > > > > Ceci n'est pas un ‘int’. [...] > https://en.wikipedia.org/wiki/The_Treachery_of_Images> For anyone interested in this concept and how it relates to programming, and many other mind-expanding concepts, I cannot recommend enough the famous book Gödel, Escher, Bach: An Eternal Golden Braid by Douglas Hofstadter. It is a mighty tome, but don't be put off by the size and weight. It covers some *extremely* subtle concepts, but it works up to them in baby steps, with the aid of dialogs between Archilles and the Tortoise. -- Steve ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
[Tutor] Accessing an entry value input by the user
Hi, I am trying to create a label and an entry widget. I am not able to understand as to how to access the value input by the user in the entry widget. Label(frame1, text = "Number of species:").grid(row=0, column = 1, sticky=W) entrynumberspecies = Entry(frame1) entrynumberspecies.grid(row=0, column = 2, sticky=W) print entrynumberspecies.get() How can I make the entrynumberspecies store the value in once the user inputs it and then use that value for later part of my code? or print it for that matter. Thank you Pooja ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Python-list thread: int vs. float
On 2017-02-11 00:36, eryk sun wrote: On Sat, Feb 11, 2017 at 8:06 AM, Steven D'Aprano wrote: Valid digits for integers include 0 through 9 in decimal Note that Python 3 uses the Unicode database to determine the decimal value of characters, if any. It's not limited to the ASCII decimal digits 0-9. For example: >>> s '௧꘢୩' >>> int(s) 123 >>> print(*(unicodedata.name(c) for c in s), sep='\n') TAMIL DIGIT ONE VAI DIGIT TWO ORIYA DIGIT THREE ??? alex@X301n3:~$ python3 Python 3.4.3 (default, Nov 17 2016, 01:11:57) [GCC 4.8.4] on linux Type "help", "copyright", "credits" or "license" for more information. s Traceback (most recent call last): File "", line 1, in NameError: name 's' is not defined What your 's' represents seems quite different to 'mine.' There must be something else going on. ??? Also of interest (at least to me) was the 'magic' you demonstrated in the print function parameter list; my efforts to figure it out: word = "Hello" print((c for c in word)) at 0xb71d125c> print(*(c for c in word)) H e l l o print(*(c for c in word), sep='') Hello ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Accessing an entry value input by the user
On 11/02/17 15:28, Pooja Bhalode wrote:
> I am trying to create a label and an entry widget. I am not able to
> understand as to how to access the value input by the user in the entry
> widget.
>
> Label(frame1, text = "Number of species:").grid(row=0, column = 1, sticky=W)
> entrynumberspecies = Entry(frame1)
> entrynumberspecies.grid(row=0, column = 2, sticky=W)
>
> print entrynumberspecies.get()
You just accessed it, via the get() method. Did that not work?
> How can I make the entrynumberspecies store the value in once the user
> inputs it and then use that value for later part of my code?
You can do it the way you did above using the get() method.
But you can also do what you did for the checkboxes - use
a StringVar and attach it to the Entry widget textvariable
attribute. That way the variable will reflect whats in
the Entry automatically and if you update the variable
it will update the Entry. (Personally I prefer to use
get() in most cases but many use the StringVar technique.)
See the example at the bottom...
> or print it for that matter.
You can print it as you did above or you can store it in
a variable and then print it or you can print the StringVar:
print myEntry.get()
myVar = MyEntry.get()
print myVar
entryVar = StringVar()
myEntry = Entry(.textvariable=entryVar)
print entryVar.get()
Here is a minimal example:
from Tkinter import *
def show():
print "entry says: " + e.get()
print "Variable holds: " + v.get()
top = Tk()
v = StringVar()
e = Entry(top,textvariable=v)
e.pack()
Button(top,text="Set foobar", command=lambda : v.set("foobar")).pack()
Button(top,text="Show me", command=show).pack()
top.mainloop()
#
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos
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Re: [Tutor] Python-list thread: int vs. float
On Fri, Feb 10, 2017 at 7:59 PM, boB Stepp wrote:
> I have been following the thread "int vs. float"
> (https://mail.python.org/pipermail/python-list/2017-February/719287.html)
> on the main list. A search for the OP on the Tutor archive came up
> negative, so I am hoping he is not following Tutor tonight (Or anytime
> prior to the due date for his homework!). The central part of
> adam14711993's question is:
>
> "What I cannot figure out is how to write it so that if my user input
> is, for example, 1.5, the program will result with: Sorry, you can
> only order whole packages.
>
> "I understand that because I am starting out by assigning my
> number_purchases_str to be an int, when the user enters a float that
> is a conflict and will crash."
>
> He cannot figure out how to reliably tell if the user's input is an
> integer, float or neither.
Back in the main Python list thread, Marko Rauhamaa suggested
(https://mail.python.org/pipermail/python-list/2017-February/719322.html):
"
...
Haven't been following the discussion, but this should be simply:
ast.literal_eval("...")
...
"
This looks like it may do the trick quite concisely:
py3: import ast
py3: ast.literal_eval('5')
5
py3: ast.literal_eval('5.0')
5.0
py3: type(ast.literal_eval('5'))
py3: type(ast.literal_eval('5.0'))
It appears to reliably parse string input as to whether it is an
integer or float. However, if the input is a non-numerical string:
py3: ast.literal_eval('a')
Traceback (most recent call last):
File "", line 1, in
File "C:\Program Files\Python35\lib\ast.py", line 84, in literal_eval
return _convert(node_or_string)
File "C:\Program Files\Python35\lib\ast.py", line 83, in _convert
raise ValueError('malformed node or string: ' + repr(node))
ValueError: malformed node or string: <_ast.Name object at 0x02C9D860>
But that seems okay, as in the OP's original problem spec, he just
needed a way to determine integer, float or other non-acceptable
input. This seems to do this quite directly. I am not familiar with
"abstract syntax trees" (Python has so much very interesting stuff!).
I am concerned about this paragraph at the beginning of the docs on it
(https://docs.python.org/3/library/ast.html?highlight=ast.literal_eval#module-ast):
"The ast module helps Python applications to process trees of the
Python abstract syntax grammar. The abstract syntax itself might
change with each Python release; this module helps to find out
programmatically what the current grammar looks like."
That statement about potentially changing with each Python release
bothers me. Should I be bothered? The link to ast.literal_eval():
https://docs.python.org/3/library/ast.html?highlight=ast.literal_eval#ast.literal_eval
What are the gotchas or other negatives from this approach?
boB
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Re: [Tutor] Python-list thread: int vs. float
On Sat, Feb 11, 2017 at 11:10 AM, Alex Kleider wrote: > Also of interest (at least to me) was the 'magic' you demonstrated in the > print function parameter list; my efforts to figure it out: Isn't this just argument unpacking? Thus the necessary "*". word = "Hello" print((c for c in word)) Need print(*(c...)) to unpack the sequence arguments. > at 0xb71d125c> print(*(c for c in word)) > > H e l l o Spaces because of the default setting for sep argument for print() as you demonstrate next. print(*(c for c in word), sep='') > > Hello -- boB ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Python-list thread: int vs. float
On Sat, Feb 11, 2017 at 11:10 AM, Alex Kleider wrote: > On 2017-02-11 00:36, eryk sun wrote: >> >> Note that Python 3 uses the Unicode database to determine the decimal >> value of characters, if any. It's not limited to the ASCII decimal >> digits 0-9. For example: >> >> >>> s >> '௧꘢୩' >> >>> int(s) >> 123 >> >>> print(*(unicodedata.name(c) for c in s), sep='\n') >> TAMIL DIGIT ONE >> VAI DIGIT TWO >> ORIYA DIGIT THREE > > > ??? > alex@X301n3:~$ python3 > Python 3.4.3 (default, Nov 17 2016, 01:11:57) > [GCC 4.8.4] on linux > Type "help", "copyright", "credits" or "license" for more information. s > > Traceback (most recent call last): > File "", line 1, in > NameError: name 's' is not defined > What your 's' represents seems quite different to 'mine.' > There must be something else going on. I suspect Eryk had set a normal 's' as an identifier for the character code sequence that produces the non-ASCII output, but forgot to show us that step. But I could be mistaken. Today I am working in Windows 7, not Linux Mint. Of course when I attempted to copy and paste the non-ASCII sequence from Gmail into cmd.exe I got 3 rectangular boxes on the paste line, indicating cmd.exe could not translate those characters. However, if I paste them into IDLE or gvim, things are translated correctly: Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 bit (AMD64)] on win32 Type "copyright", "credits" or "license()" for more information. >>> s Traceback (most recent call last): File "", line 1, in s NameError: name 's' is not defined >>> '௧꘢୩' '௧꘢୩' >>> I think that this demonstrates that 's' is just an identifier pointing to the non-ASCII character sequence, but that the actual characters can be copied and pasted *if* the editor or environment you paste those characters into is setup to translate those characters. boB ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Python-list thread: int vs. float
On Sat, Feb 11, 2017 at 2:06 AM, Steven D'Aprano wrote:
> On Fri, Feb 10, 2017 at 07:59:04PM -0600, boB Stepp wrote:
>
>> He cannot figure out how to reliably tell if the user's input is an
>> integer, float or neither. So I thought I would come up with my
>> solution, which currently is:
>>
>> py3: def ck_input():
>> ... value_to_ck = input('Enter a number:')
>> ... try:
>> ... value = int(value_to_ck)
>> ... print('You have entered an integer.')
>> ... except ValueError:
>> ... try:
>> ... value = float(value_to_ck)
>> ... print('You have entered a float.')
>> ... except ValueError:
>> ... print('You have failed to enter a numerical value.')
>> ...
> The only not-so-good part of this is that you have mixed user-interface
> and internal calculation. Better:
>
>
> def to_number(string):
> """Convert string to either an int or a float, or raise ValueError."""
> try:
> return int(string)
> except ValueError:
> return float(string)
>
>
> def check_input():
> value_to_ck = input('Enter a number: ')
> try:
> value = to_number(value_to_ck)
> except ValueError:
> print('You have failed to enter a numerical value.')
> return
> if isinstance(value, float):
> print('You have entered a float.')
> else:
> print('You have entered an int.')
>
>
> This gives you nice separation between the function that interacts with
> the user, and the function that does the actual conversion.
Ah! I am glad I asked the questions. There is a difference between
intellectually understanding what I should do and reliably
implementing it in my regular coding practice. This is one such
instance, probably of many unfortunately. I knew something was
bothering me about this. I did not like nesting try...except
two-deep. Now that you have shown the way, I see what was nagging at
me. Thanks, Steve!
boB
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Re: [Tutor] Accessing an entry value input by the user
Hi Alan,
I had done what you suggested here, I also tried creating another file for
that snipet of the code to see if that section works. The other file works,
but I am not able to figure out why the original one doesn't work.
The variable here is entrynumberspeciesvar
Code:
from Tkinter import *
import datetime
import tkMessageBox
from tkFileDialog import *
from tkMessageBox import *
root = Tk()
root.title("Design of Experiments with Parameter Estimation")
root.geometry("1000x1000")
statusvar = StringVar()
statusvar = "Status Bar"
var1 = IntVar()
var2 = IntVar()
var3 = IntVar()
var4 = IntVar()
varreac = IntVar()
varint = IntVar()
varpro = IntVar()
varconc = IntVar()
vartemp = IntVar()
entrynumberspeciesvar = IntVar()
def DesignPoint():
print "Inside Design Point"
rootdesign=Tk()
rootdesign.title("Design Point Suggestions")
rootdesign.geometry("700x400")
frame1 = Frame(rootdesign)
frame1.grid(row=0, column=0)
label1 = Label(frame1, text="1. Responses to include: ")
label1.grid(row=0, column=0,sticky=W)
Label(frame1, text = "Number of species:").grid(row=0, column = 1,
sticky=W)
entrynumberspecies = Entry(frame1, textvariable = entrynumberspeciesvar)
entrynumberspecies.grid(row=0, column = 2, sticky=W)
# print entrynumberspeciesvar.get()
checkreac = Checkbutton(frame1, text = "Reactant species", variable =
varreac)
checkreac.grid(row = 1, column = 1, sticky = W)
checkreac.select()
Checkbutton(frame1, text = "Intermediate species", variable =
varint).grid(row = 2, column = 1, sticky = W)
Checkbutton(frame1, text = "Product species", variable =
varpro).grid(row = 3, column = 1, sticky = W)
def Default():
print "Inside default"
var1.set(0)
var2.set(0)
var3.set(0)
var4.set(1)
Checkbutton(frame1, text = "Vertices", variable=var1, onvalue=1,
offvalue=0).grid(row=1, column = 2, sticky=W)
Checkbutton(frame1, text = "Edges", variable=var2).grid(row=2, column =
2, sticky=W)
Checkbutton(frame1, text = "Faces", variable=var3).grid(row=3, column =
2, sticky=W)
check = Checkbutton(frame1, text = "Center", variable=var4)
check.grid(row=4, column = 2, sticky=W)
check.select()
Label(frame1, text="2. Variables to be adjusted:").grid(row=5,
column=0,sticky=W)
Checkbutton(frame1, text = "Concentration", variable=varconc,
onvalue=1, offvalue=0).grid(row=5, column = 1, sticky=W)
Checkbutton(frame1, text = "Temperature", variable=vartemp).grid(row=6,
column = 1, sticky=W)
def InsertRange():
print "Inside InsertRange"
# entrynumberspeciesvar.set(2)
print entrynumberspeciesvar.get()
for i in range(entrynumberspeciesvar.get()):
textvar = StringVar()
print i
textvar = "\t Conc"+str(i)
Label(frame1, text=textvar).grid(row=(9+i), column=0,sticky=W)
conclowerentry = Entry(frame1)
conclowerentry.grid(row= (9+i), column = 1, sticky = W)
concupperentry = Entry(frame1)
concupperentry.grid(row= (9+i), column = 2, sticky = W)
Label(frame1, text="3. Range of formulation:").grid(row=7,
column=0,sticky=W)
Button(frame1, text = "Insert Range", command = InsertRange()).grid(row
= 7, column = 3, sticky=W)
Label(frame1, text="Lower Limit").grid(row=7, column=1,sticky=W)
Label(frame1, text="Upper Limit").grid(row=7, column=2,sticky=W)
Label(frame1, text="\t Temperature").grid(row=8, column=0,sticky=W)
templowerentry = Entry(frame1, text="0.0")
templowerentry.grid(row= 8, column = 1, sticky = W)
tempupperentry = Entry(frame1)
tempupperentry.grid(row= 8, column = 2, sticky = W)
rootdesign.mainloop()
## Secondary menu bar:
menusec = Frame(root, bg="white")
butt1 = Button(menusec, text="Part One", command=DesignPoint)
butt1.pack(side=LEFT, padx=1)
menusec.pack(side=TOP, fill=X)
### --- Status bar
Status = Label(root, text = statusvar, bd=1, relief=SUNKEN, anchor=W)
Status.pack(side=BOTTOM, fill=X)
text = Text(root, width=1000, height = 400)
text.pack(side=BOTTOM)
root.mainloop()
I have removed other parts of the code and included only the ones related
to the entry box and the work that I need to do.
I also tried doing it in another file as mentioned before. That works the
exact way I want.
Code:
from Tkinter import *
rootdesign=Tk()
rootdesign.title("Design Point Suggestions")
rootdesign.geometry("650x400")
frame1 = Frame(rootdesign)
frame1.grid(row=0, column=0)
entrynumberspeciesvar = IntVar()
## Inserting Checkboxes:
label1 = Label(frame1, text="1. Responses to include: ")
label1.grid(row=0, column=0,sticky=W )
Label(frame1, text = "Number of species:").grid(row=0, column = 1, sticky=W)
entrynumberspecies = Entry(frame1, textvariable = entrynumberspeciesvar)
entrynumberspecies.grid(row=0, column = 2, sticky=W)
def Print():
print entrynumberspeciesvar.get()
for i in range(entrynumberspeciesv
Re: [Tutor] Find (list) strings in large textfile
It is probably better to store your key file in memory
then loop over the large data file and check the
line against each key. Better to check 2000 data
keys in memory for one loop of the data file.
That way you only read the key file and data file
once each - 502,000 reads instead of a billion.
I replace one loop (in file), with searching in a *list*, and it's much
faster :)
my_list = open("list_file.txt")
file_list = [i[:-1] for i in my_list.readlines()]
file_large = open("large_file.txt")
save_file = open("output.txt", "w")
for row in file_large:
split_row = row.split()
if split_row[0] in file_list:
save_file.write(row)
file_large.close()
file_list.close()
thx for all
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Re: [Tutor] Find (list) strings in large textfile
Believe it or not, a change in two characters should make this even faster. :)
Change the line:
file_list = [i[:-1] for i in my_list.readlines()]
to:
file_list = {i[:-1] for i in my_list.readlines()}
The change is to use a "set comprehension" instead of a "list
comprehension". Sets allow membership checks in expected *constant*
time instead of *linear* time. Try that, and compare the speed: you
should get a fairly good speedup.
See:
https://docs.python.org/3/tutorial/datastructures.html#sets
for some more details.
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Re: [Tutor] Accessing an entry value input by the user
On 11/02/17 18:59, Pooja Bhalode wrote:
> Hi Alan,
>
> I had done what you suggested here, I also tried creating another file for
> that snipet of the code to see if that section works. The other file works,
> but I am not able to figure out why the original one doesn't work.
Too late at night for a detailed analysis but your code
should be restructured its ghetting very messy and hard
to see whats going on. More on that another time.
Meanwhile some immediate thoughts...
> from Tkinter import *
> import datetime
> import tkMessageBox
> from tkFileDialog import *
> from tkMessageBox import *
If you do this there's no point in importing tkmessagebox earlier.
> root = Tk()
> root.title("Design of Experiments with Parameter Estimation")
> root.geometry("1000x1000")
>
> statusvar = StringVar()
> statusvar = "Status Bar"
You create the stringvar but then throw it waay by overwriting it with a
string.
Maybe you meant to do:
statusvar = StringVar()
statusvar.set("Status Bar")
???
> var1 = IntVar()
> var2 = IntVar()
> var3 = IntVar()
> var4 = IntVar()
>
> varreac = IntVar()
> varint = IntVar()
> varpro = IntVar()
>
> varconc = IntVar()
> vartemp = IntVar()
> entrynumberspeciesvar = IntVar()
You can only use a stringvar with an Entry because
the Entry only holds text, not integers. You will
need to do the conversions yourself when you set/get
the values.
> def DesignPoint():
> print "Inside Design Point"
> rootdesign=Tk()
You are still creating multiple roots, that is
really bad practice and almost sure to create
problems later. Define the function as:
def DesignPoint(root):...
and call it as
DesignPoint(root)
> rootdesign.title("Design Point Suggestions")
> rootdesign.geometry("700x400")
> frame1 = Frame(rootdesign)
> frame1.grid(row=0, column=0)
>
If you want a second window you should be
using a Toplevel widget not Frame here.
> label1 = Label(frame1, text="1. Responses to include: ")
> label1.grid(row=0, column=0,sticky=W)
>
>
> Label(frame1, text = "Number of species:").grid(row=0, column = 1,
> sticky=W)
> entrynumberspecies = Entry(frame1, textvariable = entrynumberspeciesvar)
> entrynumberspecies.grid(row=0, column = 2, sticky=W)
>
> # print entrynumberspeciesvar.get()
> checkreac = Checkbutton(frame1, text = "Reactant species", variable =
> varreac)
> checkreac.grid(row = 1, column = 1, sticky = W)
> checkreac.select()
> Checkbutton(frame1, text = "Intermediate species", variable =
> varint).grid(row = 2, column = 1, sticky = W)
> Checkbutton(frame1, text = "Product species", variable =
> varpro).grid(row = 3, column = 1, sticky = W)
>
> def Default():
> print "Inside default"
>
> var1.set(0)
> var2.set(0)
> var3.set(0)
> var4.set(1)
This function really should be defined outside
the DesignPoint one. It will be much easier to maintain
if you separate them out.
> Checkbutton(frame1, text = "Vertices", variable=var1, onvalue=1,
> offvalue=0).grid(row=1, column = 2, sticky=W)
> Checkbutton(frame1, text = "Edges", variable=var2).grid(row=2, column =
> 2, sticky=W)
> Checkbutton(frame1, text = "Faces", variable=var3).grid(row=3, column =
> 2, sticky=W)
> check = Checkbutton(frame1, text = "Center", variable=var4)
>
> check.grid(row=4, column = 2, sticky=W)
> check.select()
>
> Label(frame1, text="2. Variables to be adjusted:").grid(row=5,
> column=0,sticky=W)
> Checkbutton(frame1, text = "Concentration", variable=varconc,
> onvalue=1, offvalue=0).grid(row=5, column = 1, sticky=W)
> Checkbutton(frame1, text = "Temperature", variable=vartemp).grid(row=6,
> column = 1, sticky=W)
>
> def InsertRange():
> print "Inside InsertRange"
> # entrynumberspeciesvar.set(2)
> print entrynumberspeciesvar.get()
> for i in range(entrynumberspeciesvar.get()):
> textvar = StringVar()
> print i
> textvar = "\t Conc"+str(i)
Again you have deleted your StringVar object by overwriting it.
You need to set the value with the set() method. OTOH you
never use the StringVar so maybe you just need to delete
that line.
> Label(frame1, text=textvar).grid(row=(9+i), column=0,sticky=W)
> conclowerentry = Entry(frame1)
> conclowerentry.grid(row= (9+i), column = 1, sticky = W)
> concupperentry = Entry(frame1)
> concupperentry.grid(row= (9+i), column = 2, sticky = W)
>
Same goes here. You should have very good reasons to define event
handlers inside the functions that build your UIs. It usually just makes
the code more complex with no benefit.
> Label(frame1, text="3. Range of formulation:").grid(row=7,
> column=0,sticky=W)
> Button(frame1, text = "Insert Range", command = InsertRange()).grid(row
> = 7, column = 3, sticky=W)
> Label(frame1, text="Lower Limit").grid(row=7, column=1,sticky=W)
> Label(frame1, text="Upper
Re: [Tutor] Python-list thread: int vs. float
On Sat, Feb 11, 2017 at 02:28:42PM -0600, boB Stepp wrote:
> Back in the main Python list thread, Marko Rauhamaa suggested
> (https://mail.python.org/pipermail/python-list/2017-February/719322.html):
>
> "
> ...
> Haven't been following the discussion, but this should be simply:
>
>ast.literal_eval("...")
> ...
> "
>
> This looks like it may do the trick quite concisely:
Nope. Not even close. The problem is that you have to accept ints and
floats, but reject anything else, and literal_eval does not do that.
py> import ast
py> ast.literal_eval('[1, {}, None, "s", 2.4j, ()]')
[1, {}, None, 's', 2.4j, ()]
literal_eval will parse and evaluate anything that looks like one of:
- int
- float
- string
- bool (True or False)
- None
- complex (e.g. -3.5+4.5j)
- tuple
- list
- dict
- set
so it does *far* more than what the OP requires.
[...]
> That statement about potentially changing with each Python release
> bothers me. Should I be bothered?
No. In this case, you are parsing a string, and the ast module itself
parses it to an Abstract Syntax Tree before evaluating literals, so it
doesn't matter if the AST is different from one version to the next.
You should only care if you generated an AST in (say) Python 3.5, saved
it in a data file, then read it back in to Python 3.6 and tried to
evaluate it. That may not succeed.
--
Steve
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Re: [Tutor] Python-list thread: int vs. float
On Sat, Feb 11, 2017 at 09:10:04AM -0800, Alex Kleider wrote:
> What your 's' represents seems quite different to 'mine.'
> There must be something else going on.
> ???
I think there's an easy explanation for that, which is that eryksun
probably just created a variable "s" but didn't show the code for that.
Unfortunately copying and pasting Unicode characters from email to the
Python interpreter may not always work, as that depends on how well at
least four software components deal with Unicode:
- the email program
- the copy/paste clipboard manager
- the console/terminal
- the Python interpreter
The second last one is particularly problematic under Windows.
When clarity is more important than brevity, the best way to insert
Unicode characters into a string is to use the '\N{name}' form:
s = '\N{TAMIL DIGIT ONE}\N{VAI DIGIT TWO}\N{ORIYA DIGIT THREE}'
Since that's pure ASCII, you can copy and paste it easily even in the
most poorly-configured system.
> Also of interest (at least to me) was the 'magic' you demonstrated in
> the print function parameter list; my efforts to figure it out:
> >>>word = "Hello"
> >>>print((c for c in word))
> at 0xb71d125c>
> >>>print(*(c for c in word))
> H e l l o
> >>>print(*(c for c in word), sep='')
> Hello
Indeed: the leading * is just the systax for argument unpacking. If you
have a sequence:
seq = [1, 2, 3, 4]
and unpack it:
print(*seq)
then what the print function sees is:
print(1, 2, 3, 4)
It works with any iterable, not just lists or tuples: also strings,
generator expressions, and more.
--
Steve
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Re: [Tutor] Python-list thread: int vs. float
On Sat, Feb 11, 2017 at 7:08 PM, Steven D'Aprano wrote:
> On Sat, Feb 11, 2017 at 02:28:42PM -0600, boB Stepp wrote:
>
>> Back in the main Python list thread, Marko Rauhamaa suggested
>> (https://mail.python.org/pipermail/python-list/2017-February/719322.html):
>>
>> "
>> ...
>> Haven't been following the discussion, but this should be simply:
>>
>>ast.literal_eval("...")
>> ...
>> "
>>
>> This looks like it may do the trick quite concisely:
>
> Nope. Not even close. The problem is that you have to accept ints and
> floats, but reject anything else, and literal_eval does not do that.
>
> py> import ast
> py> ast.literal_eval('[1, {}, None, "s", 2.4j, ()]')
> [1, {}, None, 's', 2.4j, ()]
My intent was to follow up with
type(ast.literal_eval(string_input_from_user)) and if that does not
come out 'int' or 'float', then it can be rejected as invalid input
from the user. In your example type() would return a list, which
would be invalid input for the OP's case. Of course this seems like
swatting a gnat with a sledge hammer, but it still seems that the
combination of checking the return of
type(ast.literal_eval(user_input)) does the job since everything that
is not float or int can be rejected as invalid input, and the float
case can get its special error message.
Or am I missing something?
boB
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