del

问题 I wrote a python script that backs up my files while I'm sleeping at night. The program is designed to run whenever the computer is on and to automatically shut down the computer after the backups are done. My code looks like this: from datetime import datetime from os import system from backup import backup while True: today = datetime.now() # Perform backups on Monday at 3:00am. if today.weekday() == 0 and today.hour == 3: print('Starting backups...') # Perform backups. backup("C:\\Users\

问题 I'm having trouble figuring out how to remove something from within a nested list. For example, how would I remove 'x' from the below list? lst = [['x',6,5,4],[4,5,6]] I tried del lst[0][0] , but I get the following result: TypeError: 'str' object doesn't support item deletion. I also tried a for loop, but got the same error: for char in lst: del char[0] 回答1: Your code works fine. Are you sure lst is defined as [['x',6,5,4],[4,5,6]] ? Because if it is, del lst[0][0] effectively deletes 'x' .

问题 I have a situation where I would want to delete and shift cells in a pandas data frame basis some conditions. My data frame looks like this : Value_1 ID_1 Value_2 ID_2 Value_3 ID_3 A 1 D 1 G 1 B 1 E 2 H 1 C 1 F 2 I 3 C 1 F 2 H 1 Now I want to compare the following conditions: ID_2 and ID_3 should always be less than or equal to ID_1. If anyone of them is greater than ID_1 then that cell should be deleted and shifted with the next column cell The output should look like the following : Value_1

问题 I'd like to remove temp build files during or after my laravel-mix build. Here's some code that I have currently, but del isn't working: const mix = require('laravel-mix'); const del = require('del'); // compile sass into temp css file mix.sass('resources/stylesheets/style.scss', 'public/css/temp.css'); // compile css mix.styles([ // other css stylesheets here... 'public/css/temp.css' // include temp css file ], 'public/css/admin.min.css'); // delete temp css file del('public/css/temp.css');

问题 I'd like to remove temp build files during or after my laravel-mix build. Here's some code that I have currently, but del isn't working: const mix = require('laravel-mix'); const del = require('del'); // compile sass into temp css file mix.sass('resources/stylesheets/style.scss', 'public/css/temp.css'); // compile css mix.styles([ // other css stylesheets here... 'public/css/temp.css' // include temp css file ], 'public/css/admin.min.css'); // delete temp css file del('public/css/temp.css');

问题 Is there a way to delete an item from a dictionary in Python? Additionally, how can I delete an item from a dictionary to return a copy (i.e., not modifying the original)? 回答1: The del statement removes an element: del d[key] However, this mutates the existing dictionary so the contents of the dictionary changes for anybody else who has a reference to the same instance. To return a new dictionary, make a copy of the dictionary: def removekey(d, key): r = dict(d) del r[key] return r The dict()

问题 Is there a way to delete an item from a dictionary in Python? Additionally, how can I delete an item from a dictionary to return a copy (i.e., not modifying the original)? 回答1: The del statement removes an element: del d[key] However, this mutates the existing dictionary so the contents of the dictionary changes for anybody else who has a reference to the same instance. To return a new dictionary, make a copy of the dictionary: def removekey(d, key): r = dict(d) del r[key] return r The dict()

问题 I am trying to delete the last item in both the rows and columns in my numpy.ndarray ( type = class numpy.ndarray ). My array has 30 rows and 180 columns (i.e. 180 values per row). I have tried numpy.delete but this simply removes the whole row/column. To illustrate what I want to achieve I created the following example in Python using and array and nested for loops: a = np.array([[[1,2,3,4,5,6],[1,2,3,4],[1,2,3,4]],[[1,2,3,4,5,6],[1,2,3,4],[1,2,3,4]],[[1,2,3,4],[1,2,3,4],[1,2,3,4]],[[1,2,3,4

问题 This is a follow-up question on Delete field from standard Django model. In short: a field can be dynamically deleted from a model that is already created, in this case the field User.email . So field email would be deleted from User without changing the code for User. See code below for example. I can dynamically delete a a field from a model(1), but that happens when the server starts and is undone when it exists. Since syncdb doesn't require the server to be running, and generally seems to

问题 I have to load this massive object A (that can weight almsot 10go) that I need to pass to a function, that extracts from it a parameter B to further exert some heavy computations on it. A = load(file) def function(A): B = transorm(A) B = compute(B) return(B) In order to free some memory (as I already had a MemoryError), I'd like to remove A from memory right after its transformation to B. I tried del but it doesn't seem to affect the existence of A at the script level. I also tried del global