在Python中迭代列表的问题 [英] Issues iterating through lists in Python

问题描述

我正在尝试解决一个简单的问题：

 userInput = input（ 按空格分隔的列表元素：）
 nums = userInput.split（）
  for  x  in  list（nums）：
y = int（x）*  3  
z = list（str（y））
     3  in  z：
 z.remove（  3）
  else ：
  print （z）

使用上面的代码;从逻辑上讲，应该从列表中删除所有出现的3。然而，这并不是所希望的。有人可以解释为什么&如何修复？



我想将用户输入的各个元素乘以3，然后从列表中删除所有3个实例并打印输出。



我也尝试过True并使用i + = 1计数和东西，但似乎无法让这个工作或我的头围绕它。感谢帮助。

输入 - 所需输出 - 当前输出
 
 1 2 3  -  6 9  - 9 
 0  -  0  -  0 
 2 6 11  -  6 18  -  [] 

我发现我应该使用的是列表理解。所以我做了一些研究，并且能够让它们发挥作用，但仍然没有达到预期的效果：

 p =输入（ 按空格分隔的列表元素：）
 nums = p.split（）
 mp = [num   num  in  nums *  3 ] 
  print （mp）
   x 列表中的class =code-keyword>（nums）：
y = int（x）*  3  
z = str（ y）
  print （z）
c = [z] 
 filtered = [chr  for  chr  in  c  if  c！=    3] 
  print （已过滤）
  for  n  in  list（z）：
 negate = [string  for  string  in  n  if  n！=   3] 
  print （否定）

输出保持不变。我不明白为什么以及如何解决这个问题？



为什么扫描列表中的字符串并将其从列表中删除是如此困难？！ ？ :(



真实地感谢帮助，因为我感觉像是面向桌面的手掌哭泣哈哈：P



我尝试过：



Stackoverflow，youtube，python文档。

解决方案

 userInput = input（ 按空格分隔的列表元素：）
 nums = userInput.split（）
  for  x  in  list （nums）：
y = int（x）*  3  
  if  y！ =  3 ：
  print （y，end = ' '）
  print （ ）

或使用清单理解

 userInput = input（ 按空格分隔的列表元素：）
 nums = userInput.split（）
 products = [int（x）*  3   for  x   nums  if  x！=   1] 
  print （产品）

I'm trying to solve what should be an easy problem:

userInput = input("list element seperated by space: ")
nums = userInput.split()
for x in list(nums):
    y = int(x) * 3
    z = list(str(y))
while "3" in z:
    z.remove("3")
else:
    print(z)

With the above code; logically, all occurrences of "3" should be removed from the list. This is not functioning as desired however. Could someone explain why & how to fix?

I want to multiply individual elements of user input by 3 and then remove all instances of 3 from the list and print off the output.

I've also tried while True and using i += 1 counts and stuff but just can't seem to get this working or my head round it. Appreciate the help.

input   - desired output - currently outputting

1 2 3   - 6 9            - 9
0       - 0              - 0
2 6 11  - 6 18           - []

I found out that what I should be using is list comprehension. So I did some research on that and have been able to get them to function, but still not as desired:

p = input("list element seperated by space: ")
nums = p.split()
mp = [num for num in nums * 3]
print(mp)
for x in list(nums):
    y = int(x) * 3
    z = str(y)
    print(z)
    c = [z]
filtered = [chr for chr in c if c != "3"]
print(filtered)
for n in list(z):
    negate = [string for string in n if n != "3"]
    print(negate)

The output remains the same. I don't understand why and how I can get around this?

Why is it so hard to scan a list for a string and remove it from the list?!? :(

Truthfully appreciate the help as I feel like desk-facing-palming-crying haha :P

What I have tried:

Stackoverflow, youtube, python documentation.

解决方案

userInput = input("list element seperated by space: ")
nums = userInput.split()
for x in list(nums):
    y = int(x) * 3
    if y != 3:
        print(y, end=' ')
print("")

or using a list comprehension

userInput = input("list element seperated by space: ")
nums = userInput.split()
products = [int(x) * 3 for x in nums if x != "1"]
print(products)

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