🌐 Mailman 3 September 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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precision handling
by Msd De Sept. 30, 2021

Sept. 30, 2021

Hello, The two same numbers generated in python 2.7 when subtracted should give zero. Instead it gives - 4.7393372903e-07. The number are given below: 176697092.941 - 176697092.941 = - 4.7393372903e-07 How would I increase the precision for the whole document in python? Thanks in advance. Regards,

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filter() builtin function
by Manprit Singh Sept. 30, 2021

Sept. 30, 2021

Dear sir, For the filter function in Python documentation , a line is written as below: Construct an iterator from those elements of *iterable* for which *function* returns true. *What does that true means - Boolen value True or true object - for example 1* *Like if I need only odd numbers from a list , what will be the correct lambda function to be placed inside the filter function ?* *lambda x: x%2 (That will return 1 for odd numbers which is a true object)* *or * *lambda x : x%2 == 1 ( Will return Boolean True for odd numbers)* *seq = [2, 3, 6, 9, 0, 7]list(filter(lambda x: x%2, seq)) gives the answer = *[3, 9, 7] seq = [2, 3, 6, 9, 0, 7] list(filter(lambda x: x%2 == 1, seq)) also gives the same answer = [3, 9, 7] Which one is the correct way to do the task solved just above in 2 ways ? Regards Manprit Singh

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Mp3 to MP4 using pyhon
by Rajesh Koot Sept. 30, 2021

Sept. 30, 2021

Hello, I just wanted to know if there is some method to convert MP3 file into MP4 using coding(running script)in python in automation. Please reply ASAP

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edit JSON or file in real time
by Julius Hamilton Sept. 29, 2021

Sept. 29, 2021

Hey, I would like to edit some data - essentially, a 2d array, a spreadsheet of rows and columns - in a live Python shell. I can imagine preferring that the file will remain in a tab-delimited .txt file, because it's very readable and easy to pass between different applications and so on. However, I also would like a smooth, convenient way to load that data into Python in a data type easy to work with in Python, i.e. lists. I also would like to make sure that if I edit something in that data structure it is saved immediately to the corresponding file. I wouldn't want to make an edit to an entry in the data in the live shell and somehow lose my progress because it wasn't written to the file. However, I don't want to explicitly execute a "write list back to file" command every time a change a value in the list. I would rather find some simple mode or mechanism where Python knows the list I am editing corresponds to a file, and it understands the correspondence. I.e., list(0) is the first entry in the tab-delimited file. Is there any way that I could edit a list's value and it would automatically write to the file? Do I need to create my own object with its own methods, rather than the native Python list? Thank you, Julius

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Valid usage of lambda expression
by Manprit Singh Sept. 29, 2021

Sept. 29, 2021

Dear sir, Suppose i have to make 3 functions in a program 1) sqr for returning square of a number 2) cube for returning cube of a number 3) cuberoot for getting cube root of a number Now if start with a function definition like this : def make_powerfunction(n): return lambda x: x**n and then : square = make_powerfunction(2) cube = make_powerfunction(3) cuberoot = make_powerfunction(1/3) and then doing some maths >>> square(3) 9 >>> cube(4) 64 >>> cuberoot(27) 3.0 My question is, is it a good practice to derive new functions in this way, as i have derived the functions square, cube and cuberoot from make_powerfunction. Regards Manprit Singh

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Looking for open source projects to contribute
by Lucas Cavalcante Sept. 27, 2021

Sept. 27, 2021

Hello dear Pythonista colleagues, I'm looking for an open-source project to contribute. I've been studying, practicing, and working with Python for the last 6 years, and Django for the last 2 years, etc. I'm currently employed in a private business, but I'm eager to "level up" as a developer. I also have this particular goal to cause a positive impact on society through coding. May you have any advice or recommendations? Looking forward to hearing from you, Lucas Cavalcante

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"*" operator to unpack argument from a list or tuple
by Manprit Singh Sept. 26, 2021

Sept. 26, 2021

Dear Sir, In python documentation there is a very good example of * as unpacking operator, as given below: ls = [3, 6] print(sum(range(*ls))) returns 12 which is a right answer, placing *ls inside range() created a sequence of numbers as given - 3, 4, 5 and their sum is 12. See here in this example there is only one iterable being unpacked inside a function call . Can we unpack more than one iterable inside function call using "*' ? Let's assume an example to find addition of all the numbers inside a list, tuple & set, using function ls = [2, 3] tu = (3, 6) st = {9, 1} The sum will be 24 The implementation is given below: def sumno(*seq): sumno = 0 for num in seq: sumno += num return sumno ls = [2, 3] tu = (3, 6) st = {9, 1} ans = sumno(*ls, *tu, *st) print(ans) returns 24, which is the right answer. If you can see, i have unpacked the list, tuple & set inside the function call, and i am concluding that all the numbers present inside the list, tuple and set will be received by formal parameter seq in the form of tuple, and hence the function sumno will return the sum of all numbers . I just need to know if i can unpack multiple iterables using * in function call or not as done in the previous example ? A second example to generate a pattern given below: 1 1 2 1 1 2 3 2 1 1 2 3 4 3 2 1 1 2 3 4 5 4 3 2 1 For the above pattern, if i write code as given below, is it correct instead of that multiple for loop version conventional example taught in schools. num = 5 for row in range(num): print(" "*(num-row-1), *range(1, row+2), *range(row, 0, -1)) Need your comments Regards Manprit Singh

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Creating a Loop
by Kaysi Matos Sept. 25, 2021

Sept. 25, 2021

I wrote this program to calculate the square root. I am needing to add a loop to be able to enter multiple integers. This is what I have so far. def main(): print("This program calculates the square root.") digit = int(input("Enter an integer number: ")) square = digit*digit print(f"Square of {digit} is {square}") main()

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A Question about coding style
by Manprit Singh Sept. 23, 2021

Sept. 23, 2021

Dear sir, If I have to write a program, that allows the user to input a number and assign it to a variable b, if the number entered is a negative number, assign 0 to variable b. At last print the value of variable b. The code that i have written is given below: b = int(input("Enter a number")) if b < 0: b = 0 print(b) See the whole if statement part is written in single line, is it acceptable ? Second example is of a for loop, which is also written in single line for i in range(6): print(i) # print values from 0 to 5,is it also acceptable ? Kindly guide Regards Manprit Singh

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