我在Python中有两个迭代,我想成对地遍历它们:
foo = (1, 2, 3)
bar = (4, 5, 6)
for (f, b) in some_iterator(foo, bar):
print "f: ", f, "; b: ", b
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它应该导致:
f: 1; b: 4
f: 2; b: 5
f: 3; b: 6
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一种方法是迭代索引:
for i in xrange(len(foo)):
print "f: ", foo[i], "; b: ", b[i]
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但这对我来说似乎有点不合时宜.有没有更好的方法呢?
Stack Overflow 上有很多关于这个一般主题的问答,但它们要么质量很差(通常是初学者的调试问题暗示的),要么以其他方式错过了目标(通常是不够通用)。至少有两种极其常见的方法会使幼稚的代码出错,初学者从关于循环的规范中获益更多,而不是从将问题作为拼写错误或关于打印所需内容的规范中获益。所以这是我尝试将所有相关信息放在同一个地方。
假设我有一些简单的代码,可以对一个值进行计算x并将其分配给y:
y = x + 1
# Or it could be in a function:
def calc_y(an_x):
return an_x + 1
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现在我想重复计算 的许多可能值x。我知道for如果我已经有要使用的值列表(或其他序列),我可以使用循环:
xs = [1, 3, 5]
for x in xs:
y = x + 1
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while或者,如果有其他逻辑来计算值序列,我可以使用循环x:
def next_collatz(value):
if value % 2 == 0:
return value // 2
else:
return 3 * value + 1
def collatz_from_19():
x = 19
while x != 1:
x …Run Code Online (Sandbox Code Playgroud) 我正在尝试创建一个新列表,执行两个 python 列表的逐元素子结构,如下所示:
from operator import add
number_villains_players = 0
villain_strength = []
player_strength = []
resulten_strength = []
def get_villain_strength(size):
villain_strength = [int(x) for x in input("Enter {} numbers of space separated strength of Villains:".format(size)).split()]
print(villain_strength)
def get_player_strength(size):
player_strength = [int(x) for x in input("Enter {} numbers of space separated energy of Players:".format(size)).split()]
print(player_strength)
def compare_strength():
#resulten_strength = [m-n for (m,n) in zip(player_strength,villain_strength)] #doesn't work
#resulten_strength = [sum(x) for x in zip(player_strength, villain_strength)] #doesn't work
#resulten_strength = [list( map(add, …Run Code Online (Sandbox Code Playgroud)