Question

如何创建这样的列表：

$ap | ? { $_.observability_Analysis -eq "1.00000000000000E+00" } | select -expand Offset_Angle | % { [float]$_ }

$ap | ? { $_.observability_Analysis -eq "1.00000000000000E+00" } | % { [float]$_.Offset_Angle }

如果我写["a","a","a",... (repeating "a" a hundred times") "b","b","b",(repeating "b" a hundred times.. )]，那么我会得到["a","b"] * 100，这不是我想要的。

有没有像这个一样简单的功能，但是给了我想要的结果？

Answer 1

只需将乘法第一和第二个元素生成的两个列表相加：

['a']*100 + ['b']*100

它比列表理解和排序更快：

python -m timeit "sorted(['a', 'b']*100)"
100000 loops, best of 3: 9.76 usec per loop

python -m timeit "[x for x in ['a', 'b'] for y in range(100)]"
100000 loops, best of 3: 5.15 usec per loop

python -m timeit "['a']*100 + ['b']*100"
1000000 loops, best of 3: 1.86 usec per loop

Answer 2

没有

localhost:8080

Answer 3

sak = ['a','b','c','d']
list = sak*100
print sorted(list)

var = ['a','b']
list = sorted(var*100)

Answer 4

from itertools import repeat

list(repeat('a',100)) +  list(repeat('b',100))

python：创建重复元素的字符串列表的便捷方法

4 个答案: