🌐 Mailman 3 March 2021 - Tutor - python.org

Scripting Calligra sheets with Python
by Jim Byrnes Jan. 31, 2022

Jan. 31, 2022

I am trying to script Calligra Sheets (formerly KSpread) with python. I have gotten some of the included example scripts to run so I know python scripting is running. I found the following snippet on their website: import KSpread sheet = KSpread.view().sheet() # swap text of B5 and C6 t1 = sheet.text("B5") t2 = sheet.text(6,3) sheet.setText("B5", t2) sheet.setText(6, 3, t1) # swap value of D7 and E8 v1 = sheet.value("D7") v2 = sheet.value(8,5) sheet.setValue("D7", v2) sheet.setValue(8, 5, v1) Error: 'str' object has no attribute 'text' File "file:///usr/share/kde4/apps/sheets/scripts/extensions/myswap.py", line 4, in <module> This error message appeared in a dialog box. I've taught myself some Python but I don't understand what is happening here. Shouldn't t1 be a sheet object? What would cause it to be a str instead? Thanks, Jim

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Ann: New Python curses book.
by Alan Gauld April 14, 2021

April 14, 2021

I've just published, in Kindle and paperback formats, my book on "Programming curses with Python". https://www.amazon.co.uk/dp/B091B85B77/ (It should be available in most other Amazon stores too) It is a complete rewrite of the Linux Documentation Project's HowTo for the C ncurses library. It has the same structure but all-new text and several new chapters. All specific to the Python curses package. I've kept the prices as low as Amazon permits (and allowing for fluctuations in their costs). As such, I will therefore make a few cents profit per book from sales (full disclosure). However, I felt this was the easiest and most effective way to get it "out there" where it could be found. I hope it's useful to somebody. Special thanks to all who provided me with feedback on its various iterations, especially Alex Kleider and Bob Stepp who stuck with it right to the end. Thanks guys. -- 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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managing sensitive data
by Alex Kleider March 31, 2021

March 31, 2021

I saw the following question raised recently on the "PowerfulPython" mailing list "How do I manage sensitive credentials in my Python code?" (One has to sign up for a course to hear the discussion.) I've faced this problem [1] and solved it by putting the 'sensitive' data (passwords) into dot files in my home directory with strict permission settings. I've not tested it but assume that the code will fail when trying to read such a file if the one running the code doesn't have permission to read it. (Not really a 'Python' solution!) Is there a better way to do this? [1] my code sends out emails and to do this needs a password to convince the mail transfer agent to accept the mail.

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creating and writing to a text file
by Phil March 30, 2021

March 30, 2021

Thank you for reading this. This is a simple task that I've carried out many times in the past but for some reason I've failed this time. I've saved the following code as "file_test.py" with open('test.txt', 'w+') as f: f.write('testing') Entering "python3 file_test.py" creates the following directory entry: 'test'$'\177''.txt' If I open and then read "'test'$'\177''.txt'" the file it does contain "testing". Why isn't the created file named test.txt? Python 3.8 running under Linux. -- Regards, Phil

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ValueError: Unable to coerce to DataFrame, shape must be (842, 1): given (3367, 1); ValueError: cannot reshape array of size 1 into shape (4)
by Anosh Kaniskar March 29, 2021

March 29, 2021

Hi Everyone, Mercedes Benz Project, where you need to cut the time a Mercedes Benz spends on the test bench.. So, before using any model, i performed pca technique to deal with the curse of dimensionality, and I started with the multiple linear regression model and Im not satisfied with the outcome, so I started using Random Forest and I successfully fitted the data on to the random forest model for eg: from sklearn.ensemble import RandomForestRegressor RFReg = RandomForestRegressor(n_estimators=500,max_depth=4, random_state = 50) RFReg.fit(X_train, y_train) y_pred_train = RFReg.predict(X_train) y_pred_train ____________________________________________ errors = abs(y_test - y_pred_train) errors This code gave me an error ~/Desktop/Desktop/anaconda3/lib/python3.8/site-packages/pandas/core/ops/__init__.py in _align_method_FRAME(left, right, axis) 661 662 else:--> 663 raise ValueError( 664 "Unable to coerce to DataFrame, shape " 665 f"must be {left.shape}: given {right.shape}" ValueError: Unable to coerce to DataFrame, shape must be (842, 1): given (3367, 1) _______________________________________________ So later I tried y_pred_train = y_pred_train.reshape(3367, 1) Here I'm looking for explanation for what is going wrong.. Regards Anosh K

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Printing without a line feed
by Phil March 25, 2021

March 25, 2021

Thank you for reading this. I want to print a range of numbers with a space between them but without a space at the end. For instance: for i in range(6): print(i, end=' ') How do I do this without the end space? I've spent hours on this even though I've managed to do what I want not long ago but I cannot remember how I did it. It's very frustrating. -- Regards, Phil

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(no subject)
by ੧ March 25, 2021

March 25, 2021

You've saved the password to access your Bitcoins on your personal computer. You have created an application that encrypts the password. To decrypt, you need to perform an operation between two integers, say A and B, as described below - 1) Let X and Y be the numbers obtained by REVERSING A and B. For example, the reverse of 123 is 321, and the reverse of 320 is 23 (leading zeroes are discarded) 2) If both X and Y are PRIME, then the answer is X + Y 3) If EXACTLY ONE of X and Y is PRIME, then the answer is A + B 4) Otherwise, the answer is A * B Your task is to write a program to help you perform this operation. Input: Two COMMA-separated integers A and B. There can be any number of white-spaces in the input. Output : A single integer that is the result of applying the operation described above on the input integers. Constraints: 1≤A,B≤100001≤A,B≤10000 Example: Input: 142 ,123 Output: 265 Explanation : The reverse of 142 is 241 (prime) and that of 123 is 321 (not prime). Hence the answer is A + B = 142 + 123 = 265 IMPORTANT : Make sure your code is modular i.e. you REUSE as much of the code as possible USING FUNCTIONS. You may LOSE MARKS if this guideline is not followed. My code is not working. How to solve it A, B = int(input()) rev1 = A[::-1] rev2 = B[::-1] X = rev1 Y = rev2 qw = min(X, Y) for i in range(1, qw+1): if X&i == 0 and Y%i == 0: hcf = i if hcf == 1: print(X+Y) elif: for j in range(2, X): if X%j == 0 or Y%j == 0: print(A+B) else: print(A*B)

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Re: [Tutor] string not found in variable
by jark AJ March 25, 2021

March 25, 2021

Thank you so much Dennis and Alan. Yes Dennis, understand, Somehow I got the idea that using the classes would make things easier. thank you again! Couple of follow up questions 1) At what point you would have used classes in this case or what could be the use case that would decide us to choose classes over functions 2) On the package_check() function, I am calling output = get_packages() and it does not call the package_check(). tested by printing it. When I tried to do outside of the function, I was able to get the result back. Could you please let me know why ? I am planning to use the output to perform the success/failure action using python2.7 ____ import subprocess import sys def call(cmd, shell=False): """Function for the subprocess check""" try: output = subprocess.check_call(cmd.split(), shell=shell,) return output except subprocess.CalledProcessError as error: return error.returncode except subprocess.OSError as error: return error def get_packages(): """Function to list the packages required to perform the test. nc package can be present in /usr/bin or /bin/nc""" print("test was invoked") try: nc_check_1 = call("ls /usr/bin/nc") nc_check_2 = call("ls /bin/nc") nc_check = nc_check_1 and nc_check_2 return nc_check except Exception as error: sys.exit("failed due to" + str(error)) def package_check(): """Function to check the packages required to perform the test""" output = get_packages() print(output) __ On Mon, Mar 22, 2021 at 12:17 PM Dennis Lee Bieber <wlfraed(a)ix.netcom.com> wrote: > On Sun, 21 Mar 2021 20:55:43 -0400, jark AJ <jarkmx(a)gmail.com> declaimed > the following: > > > Yes, Understood, the idea behind using a class instead of a function > >is that looking to use the same class for any commands that we may need > to > >run in future. > > You are creating an instance of the class for each command -- and > only > invoking it once, then discarding it. > > Just create a function, and pass the command to the function. > > >for i in range(5): > > command = Command("nc -zvw 4 www.google.com 443") > > output, my_check = command.run() > > print(my_check) > > print(type(output)) > > print("succeeded!" in my_check) > > That creates, runs, and disposes of five instances of Command. > > Since the command itself doesn't change inside the loop, it might > be > useful to reorder some statements -- if you insist on a class, rather than > just a function... > > >command = Command("nc -zvw 4 www.google.com 443") > >for i in range(5): > > output, my_check = command.run() > > print(my_check) > > print(type(output)) > > print("succeeded!" in my_check) > > This, at least, makes repeated use of the same instance to run the > same > command. NOTE: I've not gone back to the class definition to ensure that > there is no shared state between .run() except for the command to be run. > > > -- > Wulfraed Dennis Lee Bieber AF6VN > wlfraed(a)ix.netcom.com > http://wlfraed.microdiversity.freeddns.org/ > > _______________________________________________ > Tutor maillist - Tutor(a)python.org > To unsubscribe or change subscription options: > https://mail.python.org/mailman/listinfo/tutor >

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Re: [Tutor] How to write a loop in python to find HTML tags in a text file
by Roel Schroeven March 22, 2021

March 22, 2021

Dennis Lee Bieber schreef op 19/03/2021 om 13:07: > On Thu, 18 Mar 2021 11:11:36 -0400, Adam Eyring <adameyring(a)gmail.com> > declaimed the following: > >> I don't work with Beautiful Soup, but this chapter in the free PDF book > > Heh! You must have a different definition of "free"... > > https://automatetheboringstuff.com/ > """ > Purchase directly from the publisher to get free PDF, Kindle, and epub > ebook copies. > """ > https://nostarch.com/automatestuff2 > """ > Print Book and FREE Ebook, $39.95 > Ebook (PDF, Mobi, and ePub), $31.95 > """ > > The printed book and ebooks in PDF/Mobi/ePub are not free (well, if you buy the printed book, you get the ebook for free); but the online HTML version is free to read (scroll down to "Table of Contents"). -- "Honest criticism is hard to take, particularly from a relative, a friend, an acquaintance, or a stranger." -- Franklin P. Jones Roel Schroeven

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Fwd: Graph question was: Re: (no subject)
by Alan Gauld March 22, 2021

March 22, 2021

Forwarding to the group.... -------- Forwarded Message -------- I have written it in a more readable format. In this problem, you need to create a program for managing Graphs. The input to the program will be as described next: The first line will contain a positive integer NN. NNdenotes the number of nodes in the graph. Nodes themselves are numbered from 0 to N−1N−1. The second line will contain a non-negative integer MM(M≥0M≥0). This will be the number of edges in the graph (However, some of these could be invalid/duplicate). The next MMlines each will contain a pair of integers i,ji,jrepresenting a directed edge i→ji→j. Self edges (i→ii→i) are allowed. However, multi-edges (two or more instances of i→ji→j) have to be stored only once. Last line will contain an integer kk. The output of the program is: If kkrepresents a valid node, print all the nodes sssuch that s→ks→kis a (directed) edge in the graph. The nodes have to be in sorted order, separated by COMMA (no whitespace). If kkdoes not represent a valid node, print "ERROR: Invalid Node." EXAMPLES ___________________________________ INPUT: 3 4 0,1 1,2 2,0 0,2 2 OUTPUT: 0,1 _____________________________ INPUT: 3 4 0,1 0,2 2,0 0,2 2 OUTPUT: 0 _____________________________ INPUT: 1 0 0 OUTPUT: (Note empty output) _____________________________ NOTE: Remember that Self edges (i→ii→i) are allowed. Multi-edges (two or more instances of i→ji→j) have to be counted only once. On Sun, Mar 14, 2021 at 8:28 PM Alan Gauld <learn2program(a)gmail.com <mailto:learn2program@gmail.com>> wrote: Please supply a relevant subject line, it makes tracking the discussion much easier. On 14/03/2021 12:39, ੧ wrote: > Dear sir, I have not studies graph-related things in python. Have you studied graphs in math? Python is pretty much irrelevant since it does not directly deal in graphs. You need to do that yourself. ie. can you solve the problem below without Python? If not then that is where you must start. First understand the problem. > The first line > will contain a positive integer NN. NN denotes the number of nodes in the > graph. Nodes themselves are numbered from 0 to N−1N−1. OK, This has lost me already. The number of nodes should surely be N? Not NN? How are the nodes in a graph numbered Can you provide an example? The input samples below do not appear to match the description. Can you repost the question with clearer formatting and better examples? The more you can help us the more we can help you. > The second line will > contain a non-negative integer MM (M≥0M≥0). This will be the number of > edges in the graph (However, some of these could be invalid/duplicate). The > next MM lines each will contain a pair of integers i,ji,j representing a > directed edge i→ji→j. Self edges (i→ii→i) are allowed. However, multi-edges > (two or more instances of i→ji→j) have to be stored only once. Last line > will contain an integer kk. The output of the program is: If kk represents > a valid node, print all the nodes ss such that s→ks→k is a (directed) edge > in the graph. The nodes have to be in sorted order, separated by COMMA (no > whitespace). If kk does not represent a valid node, print "ERROR: Invalid > Node." EXAMPLES ___________________________________ INPUT: 3 4 0,1 1,2 2,0 > 0,2 2 OUTPUT: 0,1 _____________________________ INPUT: 3 4 0,1 0,2 2,0 0,2 > 2 OUTPUT: 0 _____________________________ INPUT: 1 0 0 OUTPUT: (Note empty > output) _____________________________ NOTE: Remember that Self edges (i→ii→i) > are allowed. Multi-edges (two or more instances of i→ji→j) have to be > counted only once. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ <http://www.alan-g.me.uk/> http://www.amazon.com/author/alan_gauld <http://www.amazon.com/author/alan_gauld> Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos <http://www.flickr.com/photos/alangauldphotos> -- TaranSingh

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