duplicates

given a list of string (i am not aware of list), i want to remove the duplicate and original word. for example: lst = ['a', 'b', 'c', 'c', 'c', 'd', 'e', 'e'] the output should should remove the duplicates so something like this ['a', 'b', 'd'] I do not need to preserve the order. Use a collections.Counter() object , then keep only those values with a count of 1: from collections import counter [k for k, v in Counter(lst).items() if v == 1] This is a O(N) algorithm; you just need to loop through the list of N items once, then a second loop over fewer items (< N) to extract those values that

I am using the following code to summarize my data by a column library(data.table, warn.conflicts = FALSE) library(lubridate, warn.conflicts = FALSE) ################ ## PARAMETERS ## ################ # Set path of major source folder for raw transaction data in_directory <- "C:/Users/NAME/Documents/Raw Data/" # List names of sub-folders (currently grouped by first two characters of CUST_ID) in_subfolders <- list("AA-CA", "CB-HZ") # Set location for output out_directory <- "C:/Users/NAME/Documents/YTD Master/" out_filename <- "OUTPUT.csv" # Set beginning and end of date range to be collected -

i have an array of objects like this: arr = [ {label: Alex, value: Ninja}, {label: Bill, value: Op}, {label: Cill, value: iopop} ] This array is composed when my react component is rendered. The i user Array.prototype.unshift for adding a desired element in the top of my array. So i write arr.unshift({label: All, value: All}) . When my component first rendered my array is successfully created as i desire. But when i rerender it it shows me the array with the value {label: All, value: All} as duplicate. To be more specific it is shown something like this: arr = [ {label: All, value: All},

I'm developing a single serving site in PHP that simply displays messages that are posted by visitors (ideally surrounding the topic of the website). Anyone can post up to three messages an hour. Since the website will only be one page, I'd like to control the vertical length of each message. However, I do want to at least partially preserve line breaks in the original message. A compromise would be to allow for two line breaks, but if there are more than two, then replace them with a total of two line breaks in a row. Stack Overflow implements this. For example: "Porcupines\nare\n\n\n