我们可以使用index()方法来查找“Charlie”的下标。以下是具体的代码实现: students=("Alice","Bob","Charlie","David")# 定义要查找的学生名字student_to_find="Charlie"# 使用index方法查找该学生的下标try:index=students.index(student_to_find)print(f"学生{student_to_find}的下标是:{index}")exceptValueE...
tuple_find_first (Tuple, ToFind, IndicesFindFirstB)* * 返回查找到的最后一个索引IndicesFindLastA := find_last(Tuple,ToFind)tuple_find_last (Tuple, ToFind, IndicesFindLastB)* * * 查找单个元素的替代方法是将tuple_equal_elem与 tuple_select_mask 一起使用SelectMaskA := select_mask([0:|Tuple...
std::tuple<int,int,int,int> a(2,3,1,4); std::cout<< find_index(a,1) << std::endl;//Prints 2std::cout << find_index(a,2) << std::endl;//Prints 0std::cout << find_index(a,5) << std::endl;//Prints -1 (not found)} (4)展开tuple,并将tuple元素作为函数的参数。这样...
2.7 索引 index() 查找字符串第一次出现的索引,如果找不到抛出异常ValueError。 line = 'this is line string' # ValueError: substring not found pos = line.index('line2') 1. 2. 3. 2.8 查找 find() 与index()不同的是find()如果找不到返回-1而不会抛出异常ValueError。 line = 'this is line ...
find(sub[,start[,end]]) 在指定的区间[start,end],从左至右,查找字串sub.找到返回索引,没找到放回-1 rfind(sub[,start[,end]]) 在指定的区间从右至左,和find一样 index(sub[,start[,end]]) 在指定的区间[start,end],从左至右,查找字串sub,找到返回索引,没找到就抛出异常valueError ...
index///< 泛化版本{staticintcall(std::tuple<Args...>const&t,T&&val){/// @note 如果找到该值,则返回对应索引,否则继续递归查找return(std::get<I-1>(t)==val)?I-1:find_index<I-1,T,Args...>::call(t,std::forward<T>(val));}};template<typenameT,typename...Args>structfind_index<...
typenameTupleType>constexprinttuple_index(){returntuple_index_helper<TypeForFindIndex,TupleType>::find_index_result;}structA{};structB{};structC{};usingTup=std::tuple<A,B,C>;intmain(intargc,char*argv[]){static_assert(tuple_index<A,Tup>()==0,"");static_assert(tuple_index<B,Tup>()...
tuple.findIndex( predicate[, thisArg] ) Returns the index of the first tuple element for which a provided predicate function returns a truthy value. var factory = namedtypedtuple( [ 'x', 'y', 'z' ] ); var tuple = factory( [ 1.0, 0.0, -1.0 ] ); function predicate( v ) { return...
tuple_and 功能:兩個元組的邏輯與。2. tuple_not 功能:兩個元組的邏輯非。3. tuple_or 功能:兩個元組的邏輯或。4. tuple_xor 功能:兩個元組的邏輯互斥或。 18.9 Selection1. tuple_find 功能:返回一個元組所有出現的符號,同時位於另一個元組內。2. tuple_first_n 功能:選取一個元組的第一個元素。3. ...
// CLASS tuple_element (find element by index)template<size_tIndex,classTuple>structtuple_element;// tuple_element for consttemplate<size_tIndex,classTuple>structtuple_element<Index, const Tuple>;// tuple_element for volatiletemplate<size_tIndex,classTuple>structtuple_element<Index, volatile Tuple...