Python NameError: name 'harris' is not defined - python

I apologize in advance if there is somewhere the same thread of mine.
I am new in Python programming and trying to compute an example from "Programming Computer Vision with Python" written by Jan Erik Solem.
Here is the code of the example (saved in a file called "harris.py"):
https://github.com/jesolem/PCV/blob/master/pcv_book/harris.py
(Be aware that my code ends at line 70)
After a good explanation of this code, in the book is stated: "Try running the following commands:"
im = array(Image.open(’empire.jpg’).convert(’L’))
harrisim = harris.compute_harris_response(im)
filtered_coords = harris.get_harris_points(harrisim,6)
harris.plot_harris_points(im, filtered_coords)
The problems I've encountered are two:
I am not sure where to run those last lines of code, in harris.py
or in a separate python file.
In whichever file I run it, the following error is shown:
harrisim = harris.compute_harris_response(im)
NameError: name 'harris' is not defined
I don't understand why this error is shown, since 'harris' should call the python script harris.py. Or am I wrong?

It is meant to go into a separate file, but you need to import the harris module first:
import harris
before the module is available to your code.

Harris name does not exists in your script (it was not initialised at any time before using it, so Python does not know what harris is). If import harris does not work, it is because the fact that you do not have any module called that way.

Related

Basic Rock, Paper, Scissors Doesn’t Work for my Calculator

I just started python 3, and it’s my first language. This is my first attempt at anything, and I came up with the if statements and random.randint without looking up how to make rock paper and scissors, so the whole system is very flawed. That being said, it runs beautifully on my phone, how doesn’t work for my calculator. It says something about how there is no attribute for randint, and I checked forums and they said that I must have a file already named random, but I don’t anywhere on the device. What do I do?
For some reason the app I use won’t let me copy the code, but the best I could do was a link, the code is: https://codeplayground.app/?s=cPTCDE5g4U4DBoL7UfAFkc
And the error message is: AttributeError: 'module' object has no attribute 'randint'
Edit- Sorry about improper etiquette, I do not know how to ask questions here this is my first one. Also, just to clarify, no files are named random, and this particular file was name “RPS” standing for Rock Paper Scissors
The code works for me on Colab. I assume you use a different code, where you actually use input() to capture "p".
I suggest you try
p = int(input('Let me know your number')))
I'm assuming your file name when you run and get the attribute error is random.py. If that's the case, the problem is that you are having name collision with Python's "random" module. If I copy your code into a file called random.py, I get the attribute error. If I call the file something else, like "rock_paper_scissors.py" then it runs just fine! The problem is that Python is trying to resolve randint from your own random.py file which doesn't define randint! So you have to avoid naming your files the same as the modules you want to import.
You can also test this by putting something like this at the top of your file before your call to randint:
def randint(x, y):
return 1
When you then call randint with this defined, you don't get the attribute error!

Name 'Actor' is not defined

I have a problem with python programming, when I'm trying to write a game (introduced by the book: Coding Games Python DK 3), it says:
name 'Actor' is not defined.
here's my code:
import pgzrun
from random import randint
WIDTH = 400
HEIGHT = 400
dots = []
lines = []
next_dot = 0
for dot in range(0, 10):
actor = Actor("dot")
actor.pos = randint(20, WIDTH -20), randint (20, HEIGHT - 20)
dots.append(actor)
def draw():
screen.fill("black")
number = 1
for dot in dots:
screen.draw.text(str(number), (dot.pos[0], dot.pos[1] + 12))
dot.draw()
number = number + 1
for line in lines:
screen.draw.line(line[0], line[1], (100, 0, 0))
pgzrun.go()
You are using the Python library pgzero (indirectly via importing pgzrun).
I had refactored my game code into multiple files (imported into the main file) and did also observe the same strange
NameError: name 'Actor' is not defined
error message.
The Actor class seems to be "private", but can be imported with this simple code line:
from pgzero.builtins import Actor, animate, keyboard
For background see:
https://github.com/lordmauve/pgzero/issues/61
Update Aug 18, 2019: The screen object cannot be imported since it is created as global variable during runtime (object = instance of the Screen class) and IDE-supported code completion is not possible then. See the source code: https://github.com/lordmauve/pgzero/blob/master/pgzero/game.py (esp. the def reinit_screen part)
This page on the Pygame site will help you run it from your IDE: https://pygame-zero.readthedocs.io/en/stable/ide-mode.html
Essentially, you have to have these two lines of code:
import pgzrun
...
...
pgzrun.go()
But during coding, the IDE will still complain that objects and functions like screen and Actor are undefined. Pretty annoying. As far as I know, there's no way to fix it, you just have to ignore the complaints and hit Debug > Run. Provided you have no mistakes, the program will compile and run.
With regards to
import pgzrun
actor = pgzrun.Actor("dot")
Or
from pgzrun import *
dot=Actor("dot")
Neither of these help integrated development environments like Spyder or Visual Studio recognise objects and functions like screen and Actor
pgzrun doesn't seem to behave like a normal python library.
Pygame relies on using pgzrun to run your python script from the command line:
pgzrun mygame.py
In chapter 5, page 73 of Coding Games in Python, step 2 is to save the file as numbers.py. This creates a conflict with the built in module numbers. This is the cause of the error "name 'Actor' is not defined". The solution is to save the file with a different name (i.e. follow.py).
Please define the class Actor or import it from package if you have it in your pip packages or in same dir
From what I could find on the Pygame Documentation website, Actor is defined in the pgzrun package. With your current import statements, you would have to call the Actor constructor by
actor = pgzrun.Actor("dot")
which would show the compiler that Actor belongs to pgzrun.
Alternatively, if you wanted to just use Actor("dot"), you could change your import statement to
from pgzrun import *
which means "import everything from pgzrun". This also keeps track of what comes from pgzrun and tells the compiler, but it could lead to issues (eg. if you define your own Actor constructor in your code, the compiler wouldn't know which one you're trying to use).
well I just found out It has no problem running with cmd, it has problem with running from the software itself.
So, code is correct but I might suspect something. I think you didnt upload a picture called "dot" in pgzero.
I was getting the same error message, until finally I found this topic here. The book version is missing those pgzrun first and last lines.
If you're still getting the error after putting those lines in, I bet your 'python' points to python2. Try this at the command-line:
python -V
If it shows a version of 2, you'll need to fix that. Check
which python
If it's in /usr/bin, you can do:
sudo su
cd /usr/bin
rm python
ln -s python3 python
If it's in an update-alternatives directory, you can run that program to fix it.
I had the exact same problem at the exact same code. After weeks of deleting and rewriting everything that has to do with python on my computer, I realised that it runs if you make the screen. ... lines comments by writing # in the start of each of them. I haven't found how to fix it yet, but I will inform when I will.
I found the issue. Everything on my computer was uploaded automatically to OneDrive. As a result I had a file with the same name on my computer and on OneDrive and when I tried to run it, it always ran from OneDrive where pygame and pgzero are not installed. I solved it by disconnecting auto upload and by changing the name of the file that was on my computer. Hope this works!
the solution is very simple. do not give the file a name.py name because it conflicts with python numbers.py

Enthought Canopy python - name ' ' not defined

I'm very new to using canopy and programming in general.
I'm trying to define a function in Python in the canopy editor. This used to work for me but has suddenly stopped and I have no idea why.
As a basic example, in the editor I wrote;
def funct(x):
return x
When write funct(1) in the shell I get the error message
NameError: name 'funct' is not defined
Any ideas?
Thanks
You need to "run" your script (in the editor) before its results actually exist (and are visible in) the Python shell. In this case the results of your script are to define your function. Just writing the function in the editor doesn't actually create it in Python until you run the script.
As Ali correctly said, another (deeper) approach is to import the script (in this case known as a module), but I think running is probably more what you have in mind.
I've never used Canopy before, but in general you would save the file where your function is defined somewhere in your working directory (e.g. as myfunct.py), then import it into the shell namespace:
In [1]: import myfunct
In [2]: myfunct.funct(1)
Out [2]: 1

Learn python the hard way, exercise 25

Hello everyone i am new to the python language and i have chosen learn python the hard way to learn it and to better my understanding... I am stumped on exercise 25 , When we import the code directly into the terminal
>>> import ex25
>>> sentence = "All good things come to those who wait."
>>> words = ex25.break_words(sentence)
And then I get an attribute error
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'break_words'
I am using python 2.7 on
windows 7 please help..... http://learnpythonthehardway.org/book/ex25.html
It appears to me that the exercise does not instruct the learner to save the file prior to the import. In order for this to work, you've got to save the code that defines the break_words function in a file called ex25.py using your text editor. Then, from the same directory open the python interpreter by typing:
python
and you should be able to import ex25 and run the break_words function which the ex25.py module has defined.
The code in your link for ex25.py does include that function - that yours doesn't suggests that you've somehow missed it when you transcribed the code into your file. Check that your ex25.py includes all the code from the page, and in particular contains this function (it's the very top one):
def break_words(stuff):
"""This function will break up words for us."""
words = stuff.split(' ')
return words
Consider pasting the code into your editor in preference to transcribing it in order to avoid errors like this.

Python: NameError - what should I do with this?

I am working on a large-scale software system that is written in Python right now.
The thing is, I am not sure how to make sure if each individual .py file in the system is correct. The only way for me to run the software is to run the main.py file, which uses all the other .py files.
So either everything works, or one thing doesn't (causing everything to not work).
I keep getting a NameError even when importing the correct file. I think this may have to do with the fact that the class associated with that name in the NameError may have errors in it. Any suggestions? NameError is giving me this:
File "<string>", line 1, in <module>
NameError: name 'RGBox' is not defined
It's not a very helpful error message, and I'm not sure why it's giving "string" and 'module' instead of actual values.....
[EDIT]- I am working through ssh into a remote unix machine
This is a straight-forward error message which indicates that the execution flow has not yet encountered class/module/variable RGBox prior to it being called.
RGBox is either being called out of sequence or has been mispelt.
Perform a commandline search through the app files for the name 'RGBox' or its regex equivalents. for example with grep you can do a case-insensitive search:
$ grep -lsri 'rgbox' ./my_project_folder
which will output any file which contains the patterns 'RGBox', 'rgBox', etc.
If you are unfamiliar with the code and its structure, then you may as well insert strategic logging (or print) statements at significant locations in the code to understand its flow and execution logic.

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