Archive for March, 2017
Python variable not defined
While working with a programming example for my students, I ran into an interesting run-time error when I changed their approach to importing Python’s random module. Here’s the raised error message:
Traceback (most recent call last): File "windowBouncingBalls.py", line 84, in <module> speed = [choice([-2,2]), choice([-2,2])] NameError: name 'choice' is not defined |
You raise the missing choice identifier when two things occur. The first thing requires you to use a standard import statement, like the following example, and the second thing requires you to continue to reference the identifier as “choice“.
import random |
You can avoid the error by making the import of random like this:
from random import * |
Or, you can leave the ordinary import statement and fully qualify the choice identifier with the random module name, like this:
speed = [random.choice([-2,2]), random.choice([-2,2])] |
As always, I hope this helps those who encounter a similar problem.
Install PyGame on Fedora
The PyGame library is a wonderful tool for building games with Python. It lets you accomplish a great deal by simply managing events. You need to understand how to use Python functions, modules, and events to build games with this Python library.
You can download and install the PyGame library with the yum utility like this:
yum install -y pygame |
It should generate the following list when you install it as the root user:
Loaded plugins: langpacks, refresh-packagekit Available Packages pygame.x86_64 1.9.1-14.fc20 fedora [root@localhost ~]# yum install -y pygame Loaded plugins: langpacks, refresh-packagekit Resolving Dependencies --> Running transaction check ---> Package pygame.x86_64 0:1.9.1-14.fc20 will be installed --> Processing Dependency: numpy for package: pygame-1.9.1-14.fc20.x86_64 --> Processing Dependency: libportmidi.so.0()(64bit) for package: pygame-1.9.1-14.fc20.x86_64 --> Processing Dependency: libSDL_ttf-2.0.so.0()(64bit) for package: pygame-1.9.1-14.fc20.x86_64 --> Processing Dependency: libSDL_mixer-1.2.so.0()(64bit) for package: pygame-1.9.1-14.fc20.x86_64 --> Processing Dependency: libSDL_image-1.2.so.0()(64bit) for package: pygame-1.9.1-14.fc20.x86_64 --> Running transaction check ---> Package SDL_image.x86_64 0:1.2.12-7.fc20 will be installed ---> Package SDL_mixer.x86_64 0:1.2.12-5.fc20 will be installed --> Processing Dependency: libmikmod for package: SDL_mixer-1.2.12-5.fc20.x86_64 ---> Package SDL_ttf.x86_64 0:2.0.11-4.fc20 will be installed ---> Package numpy.x86_64 1:1.8.2-2.fc20 will be installed --> Processing Dependency: python-nose for package: 1:numpy-1.8.2-2.fc20.x86_64 ---> Package portmidi.x86_64 0:217-9.fc20 will be installed --> Running transaction check ---> Package libmikmod.x86_64 0:3.3.6-3.fc20 will be installed ---> Package python-nose.noarch 0:1.3.0-1.fc20 will be installed --> Finished Dependency Resolution Dependencies Resolved ================================================================================ Package Arch Version Repository Size ================================================================================ Installing: pygame x86_64 1.9.1-14.fc20 fedora 2.1 M Installing for dependencies: SDL_image x86_64 1.2.12-7.fc20 fedora 41 k SDL_mixer x86_64 1.2.12-5.fc20 fedora 91 k SDL_ttf x86_64 2.0.11-4.fc20 fedora 22 k libmikmod x86_64 3.3.6-3.fc20 updates 142 k numpy x86_64 1:1.8.2-2.fc20 updates 3.0 M portmidi x86_64 217-9.fc20 fedora 26 k python-nose noarch 1.3.0-1.fc20 fedora 272 k Transaction Summary ================================================================================ Install 1 Package (+7 Dependent packages) Total download size: 5.7 M Installed size: 21 M Downloading packages: (1/8): SDL_image-1.2.12-7.fc20.x86_64.rpm | 41 kB 00:00 (2/8): SDL_mixer-1.2.12-5.fc20.x86_64.rpm | 91 kB 00:00 (3/8): portmidi-217-9.fc20.x86_64.rpm | 26 kB 00:00 (4/8): SDL_ttf-2.0.11-4.fc20.x86_64.rpm | 22 kB 00:00 (5/8): libmikmod-3.3.6-3.fc20.x86_64.rpm | 142 kB 00:00 (6/8): numpy-1.8.2-2.fc20.x86_64.rpm | 3.0 MB 00:02 (7/8): pygame-1.9.1-14.fc20.x86_64.rpm | 2.1 MB 00:01 (8/8): python-nose-1.3.0-1.fc20.noarch.rpm | 272 kB 00:00 -------------------------------------------------------------------------------- Total 1.7 MB/s | 5.7 MB 00:03 Running transaction check Running transaction test Transaction test succeeded Running transaction (shutdown inhibited) Installing : SDL_ttf-2.0.11-4.fc20.x86_64 1/8 Installing : SDL_image-1.2.12-7.fc20.x86_64 2/8 Installing : portmidi-217-9.fc20.x86_64 3/8 Installing : libmikmod-3.3.6-3.fc20.x86_64 4/8 Installing : SDL_mixer-1.2.12-5.fc20.x86_64 5/8 Installing : python-nose-1.3.0-1.fc20.noarch 6/8 Installing : 1:numpy-1.8.2-2.fc20.x86_64 7/8 Installing : pygame-1.9.1-14.fc20.x86_64 8/8 Verifying : pygame-1.9.1-14.fc20.x86_64 1/8 Verifying : SDL_mixer-1.2.12-5.fc20.x86_64 2/8 Verifying : python-nose-1.3.0-1.fc20.noarch 3/8 Verifying : libmikmod-3.3.6-3.fc20.x86_64 4/8 Verifying : 1:numpy-1.8.2-2.fc20.x86_64 5/8 Verifying : portmidi-217-9.fc20.x86_64 6/8 Verifying : SDL_image-1.2.12-7.fc20.x86_64 7/8 Verifying : SDL_ttf-2.0.11-4.fc20.x86_64 8/8 Installed: pygame.x86_64 0:1.9.1-14.fc20 Dependency Installed: SDL_image.x86_64 0:1.2.12-7.fc20 SDL_mixer.x86_64 0:1.2.12-5.fc20 SDL_ttf.x86_64 0:2.0.11-4.fc20 libmikmod.x86_64 0:3.3.6-3.fc20 numpy.x86_64 1:1.8.2-2.fc20 portmidi.x86_64 0:217-9.fc20 python-nose.noarch 0:1.3.0-1.fc20 Complete! |
I hope this helps folks install the software.
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