Question

嗨所以我对编程很新，所以请原谅我，如果我不能用正确的术语问，但是我正在编写一个简单的程序来完成我要转换CGS单元的作业到SI单位

例如：

if num == "1": #Gauss --> Tesla
        A=float(raw_input ("Enter value: "))
        print "=", A/(1e4), "T"

这个我只能一次转换一个值。有没有办法可以输入多个值，可能用逗号分隔并同时对所有值进行计算，然后用转换后的值吐出另一个列表？

Answer 1

您可以从用户读取逗号分隔的数字列表（可能添加空格），然后将其拆分，去除多余的空白区域，并在结果列表上循环，转换每个值，将其放入新的列表，然后最终输出该列表：

raw = raw_input("Enter values: ")
inputs = raw.split(",")
results = []
for i in inputs:
    num = float(i.strip())
    converted = num / 1e4
    results.append(converted)

outputs = []
for i in results:
    outputs.append(str(i))  # convert to string

print "RESULT: " + ", ".join(outputs)

后来，当你对Python更加流利时，你可以让它变得更好，更紧凑：

inputs = [float(x.strip()) for x in raw_input("Enter values: ").split(",")]
results = [x / 1e4 for x in inputs]
print "RESULT: " + ", ".join(str(x) for x in results)

甚至可以推荐（不推荐）：

print "RESULT: " + ", ".join(str(float(x.strip()) / 1e4) for x in raw_input("Enter values: ").split(","))

如果您想继续这样做，直到用户输入任何内容，请包装如下所示：

while True:
    raw = raw_input("Enter values: ")
    if not raw:  # user input was empty
        break
    ...  # rest of the code

Answer 2

当然！你必须提供某种＆＃34;标记＆＃34;但是，当你完成的时候。怎么样：

if num == '1':
    lst_of_nums = []
    while True: # infinite loops are good for "do this until I say not to" things
        new_num = raw_input("Enter value: ")
        if not new_num.isdigit():
            break
            # if the input is anything other than a number, break out of the loop
            # this allows for things like the empty string as well as "END" etc
        else:
            lst_of_nums.append(float(new_num))
            # otherwise, add it to the list.
    results = []
    for num in lst_of_nums:
        results.append(num/1e4)
    # this is more tersely communicated as:
    #   results = [num/1e4 for num in lst_of_nums]
    # but list comprehensions may still be beyond you.

如果您尝试输入一串以逗号分隔的值，请尝试：

numbers_in = raw_input("Enter values, separated by commas\n>> ")
results = [float(num)/1e4 for num in numbers_in.split(',')]

如果你想列出这两个，那么，构建一个字典！

numbers_in = raw_input("Enter values, separated by commas\n>> ")
results = {float(num):float(num)/1e4 for num in numbers_in.split(',')}
for CGS,SI in results.items():
    print "%.5f = %.5fT" % (CGS, SI)
    # replaced in later versions of python with:
    #   print("{} = {}T".format(CGS,SI))

在Python中处理多个输入值

2 个答案: