[英]How to print upto n elements in a list
I want to print upto 50 elements in a list我想在列表中打印最多 50 个元素
ie If there are 100 elements in the list I need first 50 alone.即如果列表中有 100 个元素,我只需要前 50 个。 My current code for the above is
我目前的上述代码是
'Filter':switcheroo.get(zaxis,["None Selected"])[zaxis].unique().tolist()[:50]
If there are 25 elements in the list I need 25 alone.如果列表中有 25 个元素,我只需要 25 个。 I get an error when the above code is used.
使用上述代码时出现错误。 from other posts I understand that the below code is the solution, but I cant understand how to implement it with my current code.'
从其他帖子我了解到以下代码是解决方案,但我无法理解如何使用我当前的代码实现它。
[x for _, x in zip(range(n), records)]
How to take the first N items from a generator or list in Python? 如何从 Python 中的生成器或列表中获取前 N 个项目?
first 50 elements of a list:列表的前 50 个元素:
print mylist[:50]
Test:测试:
newlist = [x for x in xrange(10)]
newlist2 = [x for x in xrange(100)]
print [x for x in newlist[:50]]
>[1,2,3,4,5,6,7,8,9]
print [x for x in newlist2[:50]]
>[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49]
#include <stdio.h>
#include <string.h>
struct arithmet {
char eval;
int first_num,sec_num;
};
/* function declaration */
void eval_value( struct arithmet *valyu );
int main( ) {
struct arithmet valyu1;
struct arithmet valyu2;
char oper;
int num1,num2;
gets(oper);
scanf("%d",&num1);
scanf("%d",&num1);
valyu1.first_num=num1;
valyu2.sec_num=num2;
valyu1.eval=oper;
eval_value(&num1);
eval_value(&num2);
eval_value(&per);
return 0;
}
void eval_value(struct arithmet *valyu)
{
valyu->first_num;
valyu->sec_num;
valyu->oper;
if(oper=='+')
{
printf("%d",addit(int a,int b));
}
if(oper=='-')
{
printf("%d",subtractit(int a,int b));
}
if(oper=='*')
{
printf("%d",multiplyit(int a,int b));
}
if(oper=='/')
{
printf("%d",divideit(int a,int b));
}
if(oper=='@')
{
printf("%d",intdivideit(int a,int b));
}
if(oper=='%')
{
printf("%d",remdivideit(int a,int b));
}
if(oper=='~')
{
printf("%d",exponeit(int a,int b));
}
}
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