如果否则版本可以写作如下:

sample_set="train" if "Train" in full_path else ("test" if "Test" in full_path else "validation")

有多种方式,最简单的是在“印刷”方法中使用状态。

你可以使用

print("Twenty" if number == 20 else "Not twenty")

相当于:

if number == 20:
    print("Twenty")
else:
    print("Not twenty")

因此,可以打印超过两份声明,例如:

if number == 20:
    print("Twenty")
elif number < 20:
    print("Lesser")
elif 30 > number > 20:
    print("Between")
else:
    print("Greater")

可以写作如:

print("Twenty" if number == 20 else "Lesser" if number < 20 else "Between" if 30 > number > 20 else "Greater")

特纳利条件运营商简单地允许在单一线测试一个条件,取代多线,如果它使代码紧凑。

合成:

假如他是真實的,

1、使用Ternary Operator的简单方法:

# Program to demonstrate conditional operator
a, b = 10, 20
# Copy value of a in min if a < b else copy b
min = a if a < b else b
print(min)  # Output: 10

2、直接使用Tuples、词典和Lambda的方法:

# Python program to demonstrate ternary operator
a, b = 10, 20
# Use tuple for selecting an item
print( (b, a) [a < b] )
# Use Dictionary for selecting an item
print({True: a, False: b} [a < b])
# lambda is more efficient than above two methods
# because in lambda  we are assure that
# only one expression will be evaluated unlike in
# tuple and Dictionary
print((lambda: b, lambda: a)[a < b]()) # in output you should see three 10

3、管道运营商可以写作如下:

# Python program to demonstrate nested ternary operator
a, b = 10, 20
print ("Both a and b are equal" if a == b else "a is greater than b"
        if a > b else "b is greater than a")

上面的方法可以写作如:

# Python program to demonstrate nested ternary operator
a, b = 10, 20
if a != b:
    if a > b:
        print("a is greater than b")
    else:
        print("b is greater than a")
else:
    print("Both a and b are equal")
# Output: b is greater than a

一个替代Python的条件表达

"yes" if boolean else "no"

是如下:

{True: "yes", False: "no"}[boolean]

有下列好延伸:

{True: "yes", False: "no", None: "maybe"}[boolean_or_none]

最短的替代品

("no", "yes")[boolean]

因为它是以子类(bool, int)为作用。

注意,但是:替代

yes() if boolean else no()

不是

(no(), yes())[boolean]  # bad: BOTH no() and yes() are called

但

(no, yes)[boolean]()

這工作很好,只要沒有,是的,應該用相同的數字呼叫。

yes("ok") if boolean else no()  # (1)

或在

yes("ok") if boolean else no("sorry")  # (2)

因此,相似的替代品既不存在(一)又几乎不可行(二)。(在罕见的情况下,根据背景,某种类似的

msg = ("sorry", "ok")[boolean]
(no, yes)[boolean](msg)

可以有意义( )

谢谢Radek Rojík的评论

在Python中,Ternary Operator的合成是:

假如他是真實的,

使用这个合成,这里是我们如何使用Python的Ternary操作器重写上面的代码:

game_type = 'home'
shirt = 'white' if game_type == 'home' else 'green'

请注意,表达式可能是任何类型的表达式,包括函数呼叫,返回值,评估为真实或虚假。

一个提示比一个答案更多(我不需要重复显而易见的百度),但有时我用它作为一个单线缩短在这样的结构:

if conditionX:
    print('yes')
else:
    print('nah')

它变成:

print('yes') if conditionX else print('nah')

有些(很多)可能在它上被称为无神论(甚至,Ruby-ish :),但我个人觉得它更自然 - 也就是说,你会如何正常表达它,加上在大块代码中更有视觉吸引力。