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if else python

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  if else python Scott Montreuil <scott@zml.ca> - 2015-11-25 03:45 +0000
    Re: if else python Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-25 11:10 +0000
    Re: if else python John Gordon <gordon@panix.com> - 2015-11-26 13:25 +0000

#99414 — if else python

Hi,

I have an if statement which seems to run both commands and I cannot figure out why. (just learning so I may be missing something obvious) Any ideas?

while True:
        global latit,longt,jlatit,jlongt,mlongt,mlatit
        response = urllib.urlopen(url)
        data = json.loads(response.read())
        latit = data['Data'][0]['Latitude']
        longt = data['Data'][0]['Longitude']
        jlatit = data['Data'][1]['Latitude']
        jlongt = data['Data'][1]['Longitude']
        mlatit = data['Data'][2]['Latitude']
        mlongt = data['Data'][2]['Longitude']
        for i in user1locat:
                if float(i[2]) <= float(latit) <= float(i[3]) and float(i[4]) >= float(longt) >= float(i[5]):
                        newlocation = int(i[1])
                       screen.addstr(7, 40, "%s at %s" %(user1, i[0]))
                        motor1thread = threading.Thread(target=motor1)
                        motor1thread.start()
                        screen.refresh()
                else:
                        screen.addstr(5, 40, "%s is at an unknown location %f %f\n" % (user1, latit, longt))
                        newlocation = 200
                        motor1thread = threading.Thread(target=motor1)
                        motor1thread.start()
                        screen.refresh()
        time.sleep(10)

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#99438

Scott Montreuil wrote:

> I have an if statement which seems to run both commands and I cannot
> figure out why. (just learning so I may be missing something obvious) Any
> ideas?

Use a Python IDE and debugger.  I recommend PyDev, but YMMV.

> while True:
>         global latit,longt,jlatit,jlongt,mlongt,mlatit

Why globals?  Why so many?

>         response = urllib.urlopen(url)
>         data = json.loads(response.read())
>         latit = data['Data'][0]['Latitude']
>         longt = data['Data'][0]['Longitude']

DRY.

        [latit, longt] = [data['Data'][0][key]
                          for key in ['Latitude', 'Longitude']]

There may be even more efficient ways.  Certainly the value of data['Data'] 
can be stored in a variable.

>         jlatit = data['Data'][1]['Latitude']
>         jlongt = data['Data'][1]['Longitude']
>         mlatit = data['Data'][2]['Latitude']
>         mlongt = data['Data'][2]['Longitude']

Shouts out for applying DRY.

[added line continuation escape]

>         for i in user1locat:
>                 if float(i[2]) <= float(latit) <= float(i[3]) and \
>                 float(i[4]) >= float(longt) >= float(i[5]):
>                         newlocation = int(i[1])
>                        screen.addstr(7, 40, "%s at %s" %(user1, i[0]))

["{0} at {1}".format(user1, i[0]) is recommended instead:

<https://docs.python.org/3/library/stdtypes.html#old-string-formatting>]

The indentation of the last quoted line is – as posted – one space to the 
left of that of the previous line.  That is a syntax error in Python as the 
“if” statement is 8 columns to the left instead.  Perhaps you have mixed 
tabs and spaces and that got lost while posting; in any case, this is not 
the original code, so all bets are off.

Also, 8 spaces per indentation level is too much; it certainly is too much 
to be posted to Usenet where there is a customary limit at the 80th column.
An indentation of 4 spaces per level is recommended for Python code.  If the 
code still extends beyond the 80th column, you should use a line 
continuation escape sequence if that is syntactically necessary (it is not 
in my suggestion above).

<https://www.python.org/dev/peps/pep-0008/#indentation>


-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

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#99572

In <mailman.51.1448431821.20593.python-list@python.org> Scott Montreuil <scott@zml.ca> writes:

> I have an if statement which seems to run both commands and I cannot
> figure out why.

I'm not sure what you mean by "both commands".  Do you mean that the
'if' and 'else' branches both execute?

Your if/else branches are in a loop, so perhaps you're seeing the 'if'
branch on one loop iteration, anf the 'else' branch on the next iteration?

I see that your if and else branches both contain a screen.addstr()
call.  Are you seeing both of these outputs?

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon@panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"

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