float from numbers in text file

[davidgp]

hello,
i have a text file that contains gps coordinates that i want to load
into my mysql database
the file is basically in this format:
52.2375412
5.1802704

i basically tried this:
lat =0.0
for line in f:
lat = float(line)

but this gives an error.. does anyone know what i should to do?
thanks,

 

[Stephen Hansen]

i basically tried this:
lat =0.0
for line in f:
lat = float(line)

but this gives an error.. does anyone know what i should to do?
thanks,

"An error"?

Python 2.6.1 (r261:67515, Feb 11 2010, 00:51:29)
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.... print float(line)
...
52.2375412
5.1802704

Always include what the actual error is that you're running into.

--

Stephen Hansen
... Also: Ixokai
... Mail: me+list/python (AT) ixokai (DOT) io
... Blog: http://meh.ixokai.io/


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[davidgp]

i basically tried this:
lat =0.0
for line in f:
  lat = float(line)

but this gives an error.. does anyone know what i should to do?
thanks,

"An error"?

Python 2.6.1 (r261:67515, Feb 11 2010, 00:51:29)
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.>>> f = open("test.txt", "r")
...     print float(line)
...
52.2375412
5.1802704

Always include what the actual error is that you're running into.

--

   Stephen Hansen
   ... Also: Ixokai
   ... Mail: me+list/python (AT) ixokai (DOT) io
   ... Blog:http://meh.ixokai.io/

 signature.asc
< 1KViewDownload

sorry

invalid literal for long() with base 10: '51.9449702'
this is the error i'm getting when i use long(line)

and this is the error for float(line)
invalid literal for float(): not found

cheers,

 

[Stephen Hansen]

sorry

Okay, I should be more specific: include full tracebacks and some real
copied and pasted code Don't throw away nice debugging information
Python gave you, feed it to us.

invalid literal for long() with base 10: '51.9449702'
this is the error i'm getting when i use long(line)

Yes, "51.9449702" is an invalid literal for long. Long produces
integers: no decimal points.

However:

and this is the error for float(line)
invalid literal for float(): not found

Its a perfectly valid literal for float:51.9449702

So if you're getting that error, you're doing something else that you're
not telling us.

I suspect, somehow (I'd have to see your code to be sure), that your
"line" in the second case doesn't have that number. Try it in the
interactive interpreter. float('51.9449702') works fine. I suspect your
"line", for whatever reason, contains the string "not found", as in:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: invalid literal for float(): not found

--

Stephen Hansen
... Also: Ixokai
... Mail: me+list/python (AT) ixokai (DOT) io
... Blog: http://meh.ixokai.io/


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[davidgp]

Okay, I should be more specific: include full tracebacks and some real
copied and pasted code Don't throw away nice debugging information
Python gave you, feed it to us.


Yes, "51.9449702" is an invalid literal for long. Long produces
integers: no decimal points.

However:


Its a perfectly valid literal for float:>>> float('51.9449702')

51.9449702

So if you're getting that error, you're doing something else that you're
not telling us.

I suspect, somehow (I'd have to see your code to be sure), that your
"line" in the second case doesn't have that number. Try it in the
interactive interpreter. float('51.9449702') works fine. I suspect your
"line", for whatever reason, contains the string "not found", as in:


Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for float(): not found

--

   Stephen Hansen
   ... Also: Ixokai
   ... Mail: me+list/python (AT) ixokai (DOT) io
   ... Blog:http://meh.ixokai.io/

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< 1KViewDownload

ah, i see
float("45.34") or whatever does work fine, but the problem is that i'm
reading it from a text file. so somehow it is not a real string or
whatever..
here's a part of the code:
f = open ('/home/david/out.txt', 'r')

for line in f:
if tel ==6:
buf = line.replace('\n', '')
lat = float(buf)
if tel ==7:
buf = line.replace('\n', '')
lng = float(buf)

basically it goes wrong in the last part where i try to convert the
line to a float..
i'm 100% sure that it's getting a number, not a text string

cheers!

 

[GMail Felipe]

ah, i see
float("45.34") or whatever does work fine, but the problem is that i'm
reading it from a text file. so somehow it is not a real string or
whatever..
here's a part of the code:
f = open ('/home/david/out.txt', 'r')

for line in f:
if tel ==6:
buf = line.replace('\n', '')
lat = float(buf)
if tel ==7:
buf = line.replace('\n', '')
lng = float(buf)

basically it goes wrong in the last part where i try to convert the
line to a float..
i'm 100% sure that it's getting a number, not a text string

cheers!

Ok! Just to be sure, execute the following in your <out> file:

egrep -in 'not found' <out>

If it finds something, it will return the line number and what was
found!

Felipe.

 

[Stephen Hansen]

ah, i see
float("45.34") or whatever does work fine, but the problem is that i'm
reading it from a text file. so somehow it is not a real string or
whatever..
here's a part of the code:
f = open ('/home/david/out.txt', 'r')

for line in f:
if tel ==6:
buf = line.replace('\n', '')
lat = float(buf)
if tel ==7:
buf = line.replace('\n', '')
lng = float(buf)

basically it goes wrong in the last part where i try to convert the
line to a float..
i'm 100% sure that it's getting a number, not a text string

First: you don't have to strip \n's. Try float("45.43\n")

Second: this code, as is, can't run to show us the problem because
there's this "tel" business and I don't know what it is. But I'll tweak
it a bit and:

f = open ('/Users/ixokai/out.txt', 'r')

tel = 6
for line in f:
if tel == 6:
buf = line.replace('\n', '')
lat = float(buf)
print lat
if tel == 7:
buf = line.replace('\n', '')
lng = float(buf)

And it works fine with a dummy data file I have. So... the problem is
somewhere else. Its either in your data file, or some other logic going
on (maybe something related to this 'tel' thing, I don't know).

Are you sure there's no lines in out.txt which have, say, some text (on
the left end)? Or maybe some blank lines?

Maybe you should send the whole file and the data.txt if you don't see
where the problem is.

--

Stephen Hansen
... Also: Ixokai
... Mail: me+list/python (AT) ixokai (DOT) io
... Blog: http://meh.ixokai.io/


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[davidgp]

First: you don't have to strip \n's. Try float("45.43\n")

Second: this code, as is, can't run to show us the problem because
there's this "tel" business and I don't know what it is. But I'll tweak
it a bit and:

  f = open ('/Users/ixokai/out.txt', 'r')

  tel = 6
  for line in f:
     if tel == 6:
        buf = line.replace('\n', '')
        lat = float(buf)
        print lat
     if tel == 7:
        buf = line.replace('\n', '')
        lng = float(buf)

And it works fine with a dummy data file I have. So... the problem is
somewhere else. Its either in your data file, or some other logic going
on (maybe something related to this 'tel' thing, I don't know).

Are you sure there's no lines in out.txt which have, say, some text (on
the left end)? Or maybe some blank lines?

Maybe you should send the whole file and the data.txt if you don't see
where the problem is.

--

   Stephen Hansen
   ... Also: Ixokai
   ... Mail: me+list/python (AT) ixokai (DOT) io
   ... Blog:http://meh.ixokai.io/

 signature.asc
< 1KViewDownload

i found the error! apparently something was going wrong in the loop..
thanks for the help!