[Tutor] conditional renaming folder and files in the tree
Dear Tutor,
I want to change the name of the folders and the files in the tree.
All those folders and files starting with name string '---'.
Examples:
If a folder name is : \---DAT1
I want to change this to: \changedDAT1
If a file name is: \---1.txt
I want to change this to: \changed1.txt
I have attached the code and output to this email.
Specifically, I like to provide correct syntax (dst / destination) for line 6
code block below!
I have not understood the syntax.
Thanks in advance, for your help .
best,
banda
+
for root, dirs, files in os.walk(".", topdown=False):
for name in files:
print(os.path.join(root, name))
os.rename(name.replace("---", "changed"))
list_of_files[name] = os.sep.join([dirpath, name])
print (list_of_files)
for name in dirs:
print(os.path.join(root, name))
.\---DAT1\---1.txt
---
TypeError Traceback (most recent call last)
in ()
2 for name in files:
3 print(os.path.join(root, name))
> 4 os.rename(name.replace("---", "changed"))
5 list_of_files[name] = os.sep.join([dirpath, name])
6 print (list_of_files)
TypeError: Required argument 'dst' (pos 2) not found
_end_of_email
In [1]:
import os
import sys
import glob
In [2]:
print ("Current directory is %s: " %os.getcwd())
Current directory is C:\Users\mysku\AnacondaProjects:
In [3]:
path = "E://"
# Check current working directory.
retval = os.getcwd()
print ("Current working directory %s" % retval)
# Now change the directory
os.chdir( path )
# Check current working directory.
retval = os.getcwd()
print ("Directory changed successfully %s" % retval)
Current working directory C:\Users\mysku\AnacondaProjects
Directory changed successfully E:\
In [4]:
# listing directories
print ("The dir is: %s"%os.listdir(os.getcwd()))
The dir is: ['---DAT1', '---DAT2']
In [5]:
for root, dirs, files in os.walk(".", topdown=False):
for name in files:
print(os.path.join(root, name))
for name in dirs:
print(os.path.join(root, name))
.\---DAT1\---1.txt
.\---DAT1\---2.txt
.\---DAT1\---3.txt
.\---DAT2\---5.txt
.\---DAT2\---6.txt
.\---DAT2\---7.txt
.\---DAT1
.\---DAT2
this works for root folders
for fileName in os.listdir("."): os.rename(fileName,
fileName.replace("---", "changed"))
In [6]:
for root, dirs, files in os.walk(".", topdown=False):
for name in files:
print(os.path.join(root, name))
os.rename(name.replace("---", "changed"))
list_of_files[name] = os.sep.join([dirpath, name])
print (list_of_files)
for name in dirs:
print(os.path.join(root, name))
.\---DAT1\---1.txt
---
TypeError Traceback (most recent call last)
in ()
2 for name in files:
3 print(os.path.join(root, name))
> 4 os.rename(name.replace("---", "changed"))
5 list_of_files[name] = os.sep.join([dirpath, name])
6 print (list_of_files)
TypeError: Required argument 'dst' (pos 2) not found
___
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Re: [Tutor] conditional renaming folder and files in the tree
On 11/08/17 16:10, banda gunda wrote:
> for root, dirs, files in os.walk(".", topdown=False):
> for name in files:
> print(os.path.join(root, name))
> os.rename(name.replace("---", "changed"))
Here you give the new name but not the original name.
The function needs two values, the source(original name)
and the destination(dst)
> list_of_files[name] = os.sep.join([dirpath, name])
What is dirpath? This is its first mention.
> ---
> TypeError Traceback (most recent call last)
> in ()
> > 4 os.rename(name.replace("---", "changed"))
>
> TypeError: Required argument 'dst' (pos 2) not found
See above
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos
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Re: [Tutor] Percentage of installations without setuptools (Was if __name__=='__main__' ...)
On Fri, Aug 11, 2017 at 02:35:00PM +0200, Thomas Güttler wrote: > How high is the percentage of python installation which don't have > setuptools? > > I have no clue. Is it 5%, 10%, 15% ...? > > I know there is no definite answer to this question. But you can guess this > better than me. Somewhere between 0.1% and 99.9%. For what little it is worth, out of the 9 versions of Python I have installed on my personal machines, setuptools is installed for 4 of them. On work machines, 2 out of 5 have setuptools installed. So in total, 6 out of 14 Python installations I have access to include setuptools. So 57% *don't* have setup tools. Really Thomas, why do you care? If you want to require setuptools for your packages, go right ahead. If you want to tell people that using setuptools is the best choice, or the most popular choice, or the smartest choice, do so. Just don't say it is the "default choice" because that is silly. The whole purpose of something being *default* is so that you DON'T have to make a choice. Obviously that doesn't apply to choosing a packaging library, and especially not to choosing a packaging language which may not even be present. Even if its only missing 1% of the time. As a third-party author, the sorts of people who don't have setuptools installed either won't be installing your software at all, or will be installing it from source. -- Steve ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
[Tutor] Long post: Request comments on starting code and test code on chess rating project.
I mentioned in one of the recent threads that I started that it is
probably time for me to attempt a substantial project using the OO
paradigm. I have had no coursework or training in OOP other than my
recent self-studies. Everything (Other than toy practice examples.) I
have coded to date has been strictly procedural, similar to what I
learned in FORTRAN ages ago. Also, I am continuing to try to do TDD
and keep things DRY. So I am hoping for a thorough critique of what I
will shortly present. Everything is fair game! Hopefully my
self-esteem is up to this critique!
The intent of this project is more than just calculate chess ratings.
I also envision being able to store a record of all game results and
player information for my school chess players that I give lessons to.
Some functionality I will strive to include: 1) Be able to re-rate
all games from a given date to the present. 2) Record demographic
information about my players, such as names, current school year,
current grade, etc. 3) Have a very friendly GUI so that when I have a
finished project, a student could easily take over responsibility of
maintaining the school's player ratings, if I so choose to allow this.
4) Having an editor where games and player data (But NOT ratings;
these would have to be re-rated starting from a corrected game(s).)
can be edited, inserted, or deleted with games (If game data is
edited.) automatically be re-rated. 5) Et cetera ...
My current project structure is:
/Projects
/rating_calculator
/rating_calculator
__init__.py
main.py
/tests
__init__.py
test_main.py
I have started my coding with a RatingCalculator class. The intent of
this class is to gather all methods together needed to validate and
calculate chess ratings. My intent is to only ever have a single
instance of this class existing during a given running of the program.
(BTW, is there a technique to _guarantee_ that this is always true?)
I am only at the very beginning of coding this class. I have not
added any methods yet. Currently I am adding class constants that
will be used in this class' methods. These constants are for internal
class use only and should not be altered from outside the class. Here
is the current state of the main.py program (Which will probably be
broken into multiple modules as the project develops.):
=
#!/usr/bin/env python3
"""Module to process chess ratings."""
class RatingCalculator:
"""This class contains methods to validate and calculate chess ratings."""
# Overestimated extremes for possible chess rating values. Values outside
# this range should not be achievable.
_LOWEST_POSSIBLE_RATING = 0
_HIGHEST_POSSIBLE_RATING = 3000
# Fundamental constants for use in the chess rating formula. The keys to
# these values are tuples giving the rating ranges for which these
# K-factors are valid.
_K_MULTIPLIERS = {
(_LOWEST_POSSIBLE_RATING, 2099): 0.04,
(2100, 2399): 0.03,
(2400, _HIGHEST_POSSIBLE_RATING): 0.02}
_K_ADDERS = {
(_LOWEST_POSSIBLE_RATING, 2099): 16,
(2100, 2399): 12,
(2400, _HIGHEST_POSSIBLE_RATING): 8}
=
The test code in test_main.py is:
=
#!/usr/bin/env python3
"""Module to test all functions and methods of main.py."""
import unittest
import rating_calculator.main as main
class TestRatingCalculatorConstants(unittest.TestCase):
# Check that the constants in RatingCalculator have the proper values.
def setUp(self):
# Create instance of RatingCalculator for use in the following tests.
# Create tuple of test-value pairs to interate over in subtests.
self.rating_calculator = main.RatingCalculator()
self.test_value_pairs = (
(self.rating_calculator._LOWEST_POSSIBLE_RATING, 0),
(self.rating_calculator._HIGHEST_POSSIBLE_RATING, 3000),
(self.rating_calculator._K_MULTIPLIERS[(
self.rating_calculator._LOWEST_POSSIBLE_RATING, 2099)],
0.04),
(self.rating_calculator._K_MULTIPLIERS[(2100, 2399)], 0.03),
(self.rating_calculator._K_MULTIPLIERS[(2400,
self.rating_calculator._HIGHEST_POSSIBLE_RATING)], 0.02),
(self.rating_calculator._K_ADDERS[(
self.rating_calculator._LOWEST_POSSIBLE_RATING, 2099)],
16),
(self.rating_calculator._K_ADDERS[(2100, 2399)], 12),
(self.rating_calculator._K_ADDERS[(2400,
self.rating_calculator._HIGHEST_POSSIBLE_RATING)], 8))
def test_class_constants(self):
# Check that all
Re: [Tutor] Long post: Request comments on starting code and test code on chess rating project.
I haven't had a chance to read the entire post in detail, but one thing which stands out: On Sun, Aug 13, 2017 at 12:22:52AM -0500, boB Stepp wrote: > I have started my coding with a RatingCalculator class. The intent of > this class is to gather all methods together needed to validate and > calculate chess ratings. My intent is to only ever have a single > instance of this class existing during a given running of the program. > (BTW, is there a technique to _guarantee_ that this is always true?) Yes, this is called the "Singleton" design pattern, which is very possibly the most popular and common design pattern in OOP. It is also very possibly the *least appropriate* use of OOP techniques imaginable, so much so that many people consider it to be an anti-pattern to be avoided: https://www.michaelsafyan.com/tech/design/patterns/singleton (follow the links at the bottom of the page for more information about why singletons are considered harmful). It is popular because: - it is easy to understand; - it is easy to program, at least in languages like Java and C++ (less so in Python); - consequently it is often the first OOP design patterns taught; - and it makes up for a deficiency in Java, or at least the Java philosophy, namely the lack or avoidance of top-level functions. http://steve-yegge.blogspot.com.au/2006/03/execution-in-kingdom-of-nouns.html In Python, the equivalent to the singleton is the module. If you have a class full of methods which is only ever going to be instantiated once, *almost always* the solution in Python is to use a module full of functions. There are few exceptions, but they're generally identity-objects only, with little or no state and few if any methods: - None - NotImplemented - Ellipsis - True and False (okay, duotons not singletons) I can't think of any other obvious examples. By "identity-object", I mean an object whose value is synonymous with its identity, rather than two separate aspects of the object. With regular objects, their value is independent of their identity. Their identity is "which particular object is this?" while their value is separate: you can easily have you have two floats with same value (say, both 1.25) without them necessarily being the same object. Likewise we can have two distinct lists which happen to have the same value: they both have the value [1, 2, 3], but they're different lists with the same value rather than the same list. With regular objects, just because they have the same value doesn't necessarily mean they must be the same object, they may be distinct objects with the same value. But the value of None is not separate from its identity. None has no value *except the fact that it is the None object*. Its value is not separate from its identity, its value is its identity. So, coming back to your RatingCalculator class: (1) Can you think of any possible circumstances where you might want two distinct RatingCalculators at the same time? Could you not have two different calculation methods? If so, then use a class, but allow it to be instantiated as often as you need. (2) If there is absolutely no possible reason to want two such calculators, then there is little reason to use a class at all. Singletons are just global-level state disguised as an object. A third option: Look at the source code for the random module. It has a Random class, so that you can have as many different, *independent* random number generators as you need. They can be subclassed to use different mechanisms for generating pseudo-random numbers, or they can use the same algorithm but be in different internal states. But since *most* people don't need more than one RNG at a time, there's also a hidden instance, pre-instantiated when the module is imported for the first time, which is used to provide module-level RNG functions. The caller doesn't need to know that under the hood there's a private instance. Advanced users can create their own instances, while simple cases just call the module-level functions. -- Steve ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
