我试图制作一个函数,将多个变量与一个整数进行比较,并输出一个三个字母的字符串。我想知道是否有办法将其翻译成Python。所以说:

x = 0
y = 1
z = 3
mylist = []

if x or y or z == 0:
    mylist.append("c")
if x or y or z == 1:
    mylist.append("d")
if x or y or z == 2:
    mylist.append("e")
if x or y or z == 3: 
    mylist.append("f")

其将返回以下列表:

["c", "d", "f"]

当前回答

你可以通过两种方式发展它

    def compareVariables(x,y,z):
        mylist = []
        if x==0 or y==0 or z==0:
            mylist.append('c')
        if  x==1 or y==1 or z==1:
            mylist.append('d')
        if  x==2 or y==2 or z==2:
            mylist.append('e')
        if  x==3 or y==3 or z==3:
            mylist.append('f')
        else:
            print("wrong input value!")
        print('first:',mylist)

        compareVariables(1, 3, 2)

Or

    def compareVariables(x,y,z):
        mylist = []
        if 0 in (x,y,z):
             mylist.append('c')
        if 1 in (x,y,z):
             mylist.append('d')
        if 2 in (x,y,z):
             mylist.append('e')
        if 3 in (x,y,z):
             mylist.append('f')
        else:
             print("wrong input value!")
        print('second:',mylist)

        compareVariables(1, 3, 2)

其他回答

这很容易做到

for value in [var1,var2,var3]:
     li.append("targetValue")

这里提供的所有优秀答案都集中于原始海报的具体要求,并集中于Martijn Pieters提出的if1in{x,y,z}解决方案。他们忽略了问题的更广泛含义:如何针对多个值测试一个变量?如果使用字符串,则提供的解决方案不适用于部分命中,例如:测试字符串“Wild”是否为多个值

>>> x = "Wild things"
>>> y = "throttle it back"
>>> z = "in the beginning"
>>> if "Wild" in {x, y, z}: print (True)
... 

or

>>> x = "Wild things"
>>> y = "throttle it back"
>>> z = "in the beginning"
>>> if "Wild" in [x, y, z]: print (True)
... 

对于这种情况,转换为字符串是最简单的

>>> [x, y, z]
['Wild things', 'throttle it back', 'in the beginning']
>>> {x, y, z}
{'in the beginning', 'throttle it back', 'Wild things'}
>>> 

>>> if "Wild" in str([x, y, z]): print (True)
... 
True
>>> if "Wild" in str({x, y, z}): print (True)
... 
True

然而,需要注意的是,正如@codeforester所提到的,这个方法会丢失单词boundries,如:

>>> x=['Wild things', 'throttle it back', 'in the beginning']
>>> if "rot" in str(x): print(True)
... 
True

这三个字母rot在列表中以组合形式存在,但不是单独的单词。测试“腐烂”会失败,但如果列表中的一项是“腐烂在地狱”,那也会失败。结果是,如果使用此方法,请注意搜索条件,并注意它确实有此限制。

问题

而测试多个值的模式

>>> 2 in {1, 2, 3}
True
>>> 5 in {1, 2, 3}
False

非常易读,在许多情况下都可以使用,但有一个陷阱:

>>> 0 in {True, False}
True

但我们希望

>>> (0 is True) or (0 is False)
False

解决方案

前面表达式的一个概括是基于ytpilai的答案:

>>> any([0 is True, 0 is False])
False

可以写成

>>> any(0 is item for item in (True, False))
False

虽然此表达式返回正确的结果,但其可读性不如第一个表达式:-(

单线解决方案:

mylist = [{0: 'c', 1: 'd', 2: 'e', 3: 'f'}[i] for i in [0, 1, 2, 3] if i in (x, y, z)]

Or:

mylist = ['cdef'[i] for i in range(4) if i in (x, y, z)]

要针对单个值测试多个变量,请执行以下操作:

将变量包装在集合对象中,例如{a,b,c}。使用in运算符测试值是否存储在任何变量中。如果值存储在至少一个变量中,in运算符将返回True。

# ✅ test multiple variables against single value using tuple

if 'a' in (a, b, c):
    print('value is stored in at least one of the variables')

# ---------------------------------------------------------

# ✅ test multiple variables against single value using tuple

if 'a' in {a, b, c}:
    print('value is stored in at least one of the variables')

# ---------------------------------------------------------


# ✅ test multiple variables against single value (OR operator chaining)
if a == 'a' or b == 'a' or c == 'a':
    print('value is stored in at least one of the variables')

资料来源:https://bobbyhadz.com/blog/python-test-multiple-variables-against-single-value