Be Excellent To Each Other
https://www.beexcellenttoeachother.com/forum/

Python help?
https://www.beexcellenttoeachother.com/forum/viewtopic.php?f=3&t=7310		 Page 1 of 1
Author:  kalmar [ Thu Jun 09, 2011 9:17 ]
Post subject:  Python help?
I'm attempting to program something in Python having never used it before, nor done any tutorials. Google gets you quite far but I've run into a problem and it's confusing me.

Right, so I have some bytes, in an array. Or possibly a string.

a=data[12]
print a

I get a character printed (Ý) which is obviously the ASCII character of the number I want.

I have tried using int() to convert it - and have used that elsewhere with success, but in this case I get an error - ValueError: invalid literal for int() with base 10: '\xed'

I think the problem is in understanding the type of data I've got. In C it would simply be an array of bytes, and extracting one like that gets you an integer, not a character.

?:|

Any clues?
Author:  Doctor Glyndwr [ Thu Jun 09, 2011 10:02 ]
Post subject:  Re: Python help?
Quote:
I get a character printed (Ý) which is obviously the ASCII character of the number I want.
No, it isn't. Python's handling of numeric and string types is automatic. However you're populating data[], it doesn't contain what you think it contains.
Author:  Pod [ Thu Jun 09, 2011 10:06 ]
Post subject:  Re: Python help?
type(a)

What does it say?


edit: Also, data[] is probably not an 'array', unless you explicilty made an array frmo some library like 'numpy'.
edit: and if it's a string, then data[4] would also be a string. (there's no such thing as a character).
So as Gaywood asks: How are you filling the data variable? More code plox.
Author:  kalmar [ Thu Jun 09, 2011 10:18 ]
Post subject:  Re: Python help?
It's stuff from the serial port - ser.read()
You're right, if I send ascii, I can print ascii.
It says <type 'str'>. OK.

In this case, I'm sending in numbers, like 0xED. I just need to get them out of the string, somehow.

Yeah, this is where I've got confused because in C a string and an array are interchangeable, so I wouldn't even be thinking about it.
Author:  Doctor Glyndwr [ Thu Jun 09, 2011 10:22 ]
Post subject:  Re: Python help?
To give you an idea of how it's supposed to work

Code:
C:\Users\rgaywood\workspace_SSTS_2.6.1\FBECore>python
Python 2.7 (r27:82525, Jul  4 2010, 07:43:08) [MSC v.1500 64 bit (AMD64)] on win
32
Type "help", "copyright", "credits" or "license" for more information.
>>> data = [2,3,"4"]
>>> print data[0]
2
>>> print data[0]+data[1]
5
>>> print data[2]
4
>>> print data[2]+data[1]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: cannot concatenate 'str' and 'int' objects
>>> print int(data[2])+data[1]
7
>>> print data[2]+str(data[1])
43
>>>


You're not reading your serial port correctly.
Author:  kalmar [ Thu Jun 09, 2011 10:42 ]
Post subject:  Re: Python help?
I am too! If I send 0x50 in the port, I get 'P'. Correct. That is also worth 80 in decimal, and I want that :)

VAL() in basic, possibly.. Back to google.
Author:  kalmar [ Thu Jun 09, 2011 11:11 ]
Post subject:  Re: Python help?
The answer is ORD() !

Thanks guys, you helped me understand the data type.
Author:  Mimi [ Thu Jun 09, 2011 11:25 ]
Post subject:  Re: Python help?
Well, not being able to see the subtitle, this thread was a disappointment.
:(
Author:  Pod [ Thu Jun 09, 2011 12:00 ]
Post subject:  Re: Python help?
ps:

>>> data = "\x80"
>>> print data
Ç
>>> data
'\x80'
>>> repr(data)
"'\\x80'"

>>> data = "\x50\x36\x49"
>>> print data
P6I
>>> data
'P6I'
>>> repr(data)
"'P6I'"

>>> data + "\x80"
'P6I\x80'
>>> data = data + "\x80"
>>> print data
P6IÇ
>>> data
'P6I\x80'

>>> ord("\x60")
96
>>> int("\x60")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: '`'
Author:  lasermink [ Fri Jun 10, 2011 10:07 ]
Post subject:  Re: Python help?
I think Beex just crashed.
Author:  Mr Russell [ Fri Jun 10, 2011 10:20 ]
Post subject:  Re: Python help?
lasermink wrote:
I think Beex just crashed.


Into your mum's face!
Author:  Mimi [ Sat May 16, 2020 13:04 ]
Post subject:  Re: Python help?
A friend has just sent me this asking if there is anyone I might know that might help:

An old work colleague of mine posted this on Facebook, any ideas?
—-

S.O.S my facebook pepes I need some HELP.
Any Abuntu or Python programmer could assist..
My son and I are build an autonomous rc car using donkeycar.
We keep PEMISSION DENIED after running the following command line:
python ~/mycar/manage.py train --tub ~/mycar/data/mytub --model ~/mycar/models/mypilot.h5

it error when writing back to the .h5 file

Please help as this is for his degree

Thank you all
——
Author:  myp [ Sat May 16, 2020 13:45 ]
Post subject:  Re: Python help?
Sounds like either the file is set to read-only or the user account doesn’t have the correct privileges to write to the file, rather than a programming error as such (although I don’t do Python so I can’t tell if there’s any errors there).
Author:  Mimi [ Sat May 16, 2020 19:26 ]
Post subject:  Re: Python help?
Thank you. I passed that on x
Page 1 of 1 All times are UTC [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/