英文:
How to separate strings in a list, multiplied by a number
问题
你的代码需要将列表中的每个项目都乘以4，并用逗号分隔它们。你需要的输出是每个表达式重复显示的次数乘以4，用逗号分隔。
以下是修改后的代码：
conc = ['0.05 ml : 25 ml', '0.05 ml : 37.5 ml', '0.05 ml : 50 ml', '0.05 ml : 62.5 ml', '0.05 ml : 75 ml']
new_conc = [item for item in conc for _ in range(4)]
result = ', '.join(new_conc)
print(result)
这段代码将输出你所需的结果。
英文:
I need to take a list, multiply every item by 4 and separate them by coma.
My code is:
conc = ['0.05 ml : 25 ml', '0.05 ml : 37.5 ml', '0.05 ml : 50 ml', '0.05 ml : 62.5 ml', '0.05 ml : 75 ml']
new_conc = [", ".join(i*4) for i in conc]
print(new_conc)
But when I run it, I get every SYMBOL separated by come. What I need is multiplied number of shown EXPRESSIONS separated by coma.
So the output should be:
['0.05 ml : 25 ml', '0.05 ml : 25 ml', '0.05 ml : 25 ml', '0.05 ml : 25 ml', '0.05 ml : 37.5 ml', '0.05 ml : 37.5 ml', '0.05 ml : 37.5 ml', '0.05 ml : 37.5 ml', '0.05 ml : 50 ml', '0.05 ml : 50 ml', '0.05 ml : 50 ml', '0.05 ml : 50 ml', '0.05 ml : 62.5 ml', '0.05 ml : 62.5 ml', '0.05 ml : 62.5 ml', '0.05 ml : 62.5 ml', '0.05 ml : 75 ml', '0.05 ml : 75 ml', '0.05 ml : 75 ml', '0.05 ml : 75 ml']
I found this answered question, but as I already mentioned, I get separate symbols, separated by coma.
答案1
得分: 3
你可以使用简单的 for 循环。
new_conc = []
for item in conc:
new_conc.extend([item] * 4)
英文:
You can use a simple for loop.
new_conc = []
for item in conc:
new_conc.extend([item] * 4)
答案2
得分: 1
你可以尝试使用双重循环：
conc = ['0.05 ml : 25 ml', '0.05 ml : 37.5 ml', '0.05 ml : 50 ml', '0.05 ml : 62.5 ml', '0.05 ml : 75 ml']
out = []
for item in conc:
for _ in range(4):
out.append(item)
print(out)
或者使用一行代码的方式：
out = [item for item in conc for _ in range(4)]
或者（如果输出中的顺序不重要）：
out = conc * 4
英文:
You can try double for-loop:
conc = ['0.05 ml : 25 ml', '0.05 ml : 37.5 ml', '0.05 ml : 50 ml', '0.05 ml : 62.5 ml', '0.05 ml : 75 ml']
out = []
for item in conc:
for _ in range(4):
out.append(item)
print(out)
Or one-liner:
out = [item for item in conc for _ in range(4)]
Or (if order as you stated in your output is not important):
out = conc * 4
答案3
得分: 1
你不能直接将字符串相乘，你需要从非数字部分分离出数值部分，然后进行相乘，最后重新将数值部分和字符串部分合并。
conc = ['0.05 ml : 25 ml', '0.05 ml : 37.5 ml', '0.05 ml : 50 ml', '0.05 ml : 62.5 ml', '0.05 ml : 75 ml']
multiplied_conc = [': '.join([f"{float(p.split()[0])*4} {p.split()[1]}" for p in c.split(' : ')]) for c in conc]
print(multiplied_conc)
英文:
You can't directly multiply a string, you need to "separate" the numeric part from the non-numeric one, then you can perform your multiplication, and finally rejoin the numeric and the string parts.
conc = ['0.05 ml : 25 ml', '0.05 ml : 37.5 ml', '0.05 ml : 50 ml', '0.05 ml : 62.5 ml', '0.05 ml : 75 ml']
multiplied_conc = [': '.join([f"{float(p.split()[0])*4} {p.split()[1]}" for p in c.split(' : ')]) for c in conc]
print(multiplied_conc)
答案4
得分: 0
以下是翻译好的部分：
"Okay, when I despaired of finding an answer and posted this question, I found this answered question. :)"
"So the solution to my problem can be:"
"But, if you, guys, know better solution, I will be happy to hear it!"
英文:
Okay, when I despaired of finding an answer and posted this question, I found this answered question. 
So the solution to my problem can be:
b = [4, 4, 4, 4]
c = sum([展开收缩 * n for s, n in zip(conc, b)], [])
print(c)
But, if you, guys, know better solution, I will be happy to hear it!
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