for-loop

问题 I have a simple example I've drawn up. I thought it was possible to combine if statements and for loops with minimal effort in Python. Given: sublists = [number1, number2, number3] for sublist in sublists: if sublist: print(sublist) I thought I could condense the for loop to: for sublist in sublists if sublist: but this results in invalid syntax. I'm not too particular on this example, I just want a method of one lining simple if statements with loops. 回答1: if you want to filter out all the

问题 I am writing a program in Python that reads in bank data from a file and stores it in data structures for output at a later time. I have a list that stores the transactions like D,520,W,20,D,100 Where the letter is the transaction type (Withdrawl or Deposit) and the numbers are the amount. I have a for loop that will calculate the balance, but I am having trouble getting to the next element. Essentially what I want to do is: for item in theList: if item == 'D': balance = balance + int(NEXT

问题 I am writing a program in Python that reads in bank data from a file and stores it in data structures for output at a later time. I have a list that stores the transactions like D,520,W,20,D,100 Where the letter is the transaction type (Withdrawl or Deposit) and the numbers are the amount. I have a for loop that will calculate the balance, but I am having trouble getting to the next element. Essentially what I want to do is: for item in theList: if item == 'D': balance = balance + int(NEXT

问题 I'm working on Windows. I have many jpg files in subdirectories of a directory. I don't know exactly the architecture of the directory, meaning that I don't know how many levels the subdirectories have. What I need to do is to process jpg files according to their paths. Here is an example: dir |---sub dir1 | |-----sub dir11 | |-----a.jpg | |-----b.jpg |---sub dir2 |-----c.jpg |-----d.jpg So I need to execute commands as below: process.bat C:\dir\sub dir1\sub dir11\a.jpg C:\dir\sub dir1\sub

问题 SELECT listTitle, listLength, listCmt, listDt, mBCFName, mBCLName, moAmt, moDtOff FROM User U, Listing L, Merchant M, MerchantOffer MO WHERE U.uID = L.uID and L.listID = MO.listID and M.mID = MO.mId ORDER BY listDt DESC; This foreach() loop $result = $sth->fetchAll(PDO::FETCH_ASSOC); foreach($result as $row) { echo "<div class='listing'>"; print '<br>Title: ' . $row['listTitle'] . '<br>Comment: ' . $row['listCmt'] . '<br>Date: ' . $row['listDt'] . '<br>Offer By: ' . $row['mBCFName']. ' ' .

问题 I've been stuck at this problem for some hours now, and it seems I can't find the solution by searching i.e. didn't find anything here or on Google. Here's my piece of code: LIBRARY IEEE; USE IEEE.std_logic_1164.ALL; USE IEEE.numeric_std; USE work.arrays.ALL; ENTITY parallel IS PORT (clk:IN std_logic; text:IN INT_ARRAY(119 DOWNTO 0); result:OUT INT_MATRIX_2D); END parallel; ARCHITECTURE arch OF parallel IS COMPONENT unit_comparator IS PORT (letter:IN integer; difference:OUT integer); END

问题 I need help because my brain cells cannot find what is wrong with this program! Here's the code import java.util.*; public class student{ public static void main (String []args) { Scanner sc=new Scanner(System.in); System.out.println("enter number elements"); //asking the user to enter the number of integer items int num=sc.nextInt(); int []myArray= new int[num]; int maxValue=myArray[0]; int minValue=myArray[0]; int i; for( i=0; i<myArray.length;i++) {System.out.print("Enter element"+(i+1));

问题 I have a dataframe that looks somewhat like the following. A1U_sweet is actually the 19th column in the real dataframe, and C1U_sweet is the 39th column in the real dataframe. There are 20 columns beginning with A## and 20 beginning with C##. A1U_sweet A2F_dip A3U_bbq C1U_sweet C2F_dip C3U_bbq 1 2 1 NA NA NA NA NA NA 4 1 2 2 4 7 NA NA NA I would like to make additional columns that combine the A values and the C values. The resulting dataframe would include columns looking like B1U_sweet and

问题 I have a data frame that looks like this: date time id datetime 1 2015-01-02 14:27:22.130 999000000007628 2015-01-02 14:27:22 2 2015-01-02 14:41:27.720 989001002807730 2015-01-02 14:41:27 3 2015-01-02 14:41:27.940 989001002807730 2015-01-02 14:41:27 4 2015-01-02 14:41:28.140 989001002807730 2015-01-02 14:41:28 5 2015-01-02 14:41:28.170 989001002807730 2015-01-02 14:41:28 6 2015-01-02 14:41:28.350 989001002807730 2015-01-02 14:41:28 I need to find the number of unique "id"s for each "date" in

问题 I am trying to loop through each page but once it gets to the end of the pages it just skips over the needed lines. The pages vary by by link. So I need a dynamic solution for the number of webpages. This a working example so the results will be shown in ran. The stackoverflow requires me to add more details from selenium import webdriver from selenium.webdriver.support.ui import WebDriverWait from selenium.webdriver.support import expected_conditions as EC from selenium.webdriver.common.by