如何在C#中执行Python的zip?
Python的zip
功能执行以下操作:如何在C#中执行Python的zip?
a = [1, 2, 3]
b = [6, 7, 8]
zipped = zip(a, b)
结果
[[1, 6], [2, 7], [3, 8]]
如何this?
C#4.0 LINQ的新ZIP算
public static IEnumerable<TResult> Zip<TFirst, TSecond, TResult>(
this IEnumerable<TFirst> first,
IEnumerable<TSecond> second,
Func<TFirst, TSecond, TResult> func);
名称相同,但操作完全不同。 Linq的Zip()可用于对2个输入序列产生python-zip效果,但与2个以上的序列无关。 – 2014-06-18 21:02:14
解决方案1:
IEnumerable<KeyValuePair<T1, T2>> Zip<T1, T2>(
IEnumerable<T1> a, IEnumerable<T2> b)
{
var enumeratorA = a.GetEnumerator();
var enumeratorB = b.GetEnumerator();
while (enumeratorA.MoveNext())
{
enumeratorB.MoveNext();
yield return new KeyValuePair<T1, T2>
(
enumeratorA.Current,
enumeratorB.Current
);
}
}
解决方案2:以C#4.0邮编相似,但你可以用它在C#3.0
public static IEnumerable<TResult> Zip<TFirst, TSecond, TResult>(
this IEnumerable<TFirst> first,
IEnumerable<TSecond> second,
Func<TFirst, TSecond, TResult> func)
{
using(var enumeratorA = first.GetEnumerator())
using(var enumeratorB = second.GetEnumerator())
{
while (enumeratorA.MoveNext())
{
enumeratorB.MoveNext();
yield return func(enumeratorA.Current, enumeratorB.Current);
}
}
}
当秒数比第一次短时,它会抛出异常 – 2010-03-11 17:21:40
您忘记了处理您的枚举数。 – 2010-03-11 20:24:13
@Eric感谢您的纠正。我编辑了答案 – 2010-03-11 23:40:22
此外,在Cadenza看看它有所有各种漂亮的实用方法。
具体看一下这里的邮编扩展方法: http://gitorious.org/cadenza/cadenza/blobs/master/src/Cadenza/Cadenza.Collections/Enumerable.cs#line1303
我只是遇到了同样的问题。 .NET库不提供解决方案,所以我自己做了。这是我的解决方案。
Pivot
方法作为IEnumerable<IEnumerable<T>>
的扩展。 它要求所有序列的元素都是相同类型的T
。
public static class LinqUtil
{
/// <summary>
/// From a number of input sequences makes a result sequence of sequences of elements
/// taken from the same position of each input sequence.
/// Example: ((1,2,3,4,5), (6,7,8,9,10), (11,12,13,14,15)) --> ((1,6,11), (2,7,12), (3,8,13), (4,9,14), (5,10,15))
/// </summary>
/// <typeparam name="T">Type of sequence elements</typeparam>
/// <param name="source">source seq of seqs</param>
/// <param name="fillDefault">
/// Defines how to handle situation when input sequences are of different length.
/// false -- throw InvalidOperationException
/// true -- fill missing values by the default values for the type T.
/// </param>
/// <returns>Pivoted sequence</returns>
public static IEnumerable<IEnumerable<T>> Pivot<T>(this IEnumerable<IEnumerable<T>> source, bool fillDefault = false)
{
IList<IEnumerator<T>> heads = new List<IEnumerator<T>>();
foreach (IEnumerable<T> sourceSeq in source)
{
heads.Add(sourceSeq.GetEnumerator());
}
while (MoveAllHeads(heads, fillDefault))
{
yield return ReadHeads(heads);
}
}
private static IEnumerable<T> ReadHeads<T>(IEnumerable<IEnumerator<T>> heads)
{
foreach (IEnumerator<T> head in heads)
{
if (head == null)
yield return default(T);
else
yield return head.Current;
}
}
private static bool MoveAllHeads<T>(IList<IEnumerator<T>> heads, bool fillDefault)
{
bool any = false;
bool all = true;
for (int i = 0; i < heads.Count; ++i)
{
bool hasNext = false;
if(heads[i] != null) hasNext = heads[i].MoveNext();
if (!hasNext) heads[i] = null;
any |= hasNext;
all &= hasNext;
}
if (any && !all && !fillDefault)
throw new InvalidOperationException("Input sequences are of different length");
return any;
}
}
请注意,zip可以接受任意数量的参数,而不仅仅是两个参数,如本例所示。到目前为止,答案都集中在这两个可迭代的案例上,在我看来。 – 2010-03-12 00:42:02
@杰弗里提醒。 – 2010-03-12 12:37:21