I was recently given a project to do for my Python college course. Basically, you save a dictionary in a csv file with csv.DictWriter, and then you load it back into another dictionary with csv.DictReader. However, for some reason, one of the automated unittests fails my function because the final dictionary …
Tag: boolean
How to use boolean on list correctly?
(result True) I want result become False if only one in list A or B have small value than a or b. In this code B[1] < b[1] (5 >= 10) result I expect is False but is output True Answer From official doc: The comparison uses lexicographical ordering: first the first two items are compared, and if they dif…
Cant use the Boolean operator ‘or’ in a if statement to initiate if either string contains the following characters. Only works if separate statements
Part of the project I`m working on requires me to automate arcGIS functions using python. While trying to locate files I noticed that when I included the ‘or’ operator in my if statement that the loop would stop collecting files after currentDirList no longer contained the first string. The other …
Python if statement not working correctly and no idea why
In my code I iterate through dataframes of each year to calculate the number of wins (increase between numbers) and losses (decrease between numbers), and the ratio of wins to losses. The loop I run correctly displays the right number of wins and losses in the dataframe they are eventually pushed to. However,…
How to make a boolean array by checking if the items in an array is in a list?
I’m trying to find every item in an numpy array arr that’s also in an arbitrary list lst and replace them, but while arr > 0 will generate a boolean array for easy masking, arr in lst only works with all() or any() which isn’t what I need. Example input: array (1, 2, 3, 4, 5), list [2, 4,…
Using If statement with string values in Python
I have a df where column A is either blank or has a string in it. I tried to write the if statement (all columns are strings) below. Basically, if there is something (any value) in df[A], then the new column value will be a concatenation of columns A, B and C. If there is no value in df[A], then
Python: justification for boolean operators (and, or) not returning booleans
[EDIT: this question is not a duplicate of this; I am asking a question of language design, i.e. why it is this way in the first place. I am not confused about how it behaves, I am confused about why this behavior was decided upon in the first place.] In Python (and some other languages, e.g. Lua), the boolea…
Drop rows in df based on if file name from df exists in folder
I have a dataframe which contains 40108 rows and a folder with pictures (only using a sample of the total 40108 pictures) containing 997 files. The file names of the images correspond to the rows in the column ‘imdbId’ in the df, with the addition that they have the .jpg suffix. I would like to dr…
When should I use None vs False?
From what I’ve seen, the only time None and False behave differently is when they’re compared to each other (for equality). Am I missing something, or is it ok to use only one or the other as long as you’re consistent in your usage? Is there any reason to use one over the other? Answer I wou…
Syntax for an If statement using a boolean
I just recently joined the python3 HypeTrain. However I just wondered how you can use an if statement onto a boolean. Example: And also, can I just switch the value of a boolean like this? Answer You can change the value of a bool all you want. As for an if: works, but you can also use: If you want