np.set_printoptions(precision=None, threshold=None, edgeitems=None, linewidth=None, suppress=None, nanstr=None, infstr=None)
precision :
int, optional，float输出的精度，即小数点后维数，默认8（ Number of digits of precision for floating point output (default 8)）
threshold :
int, optional，当数组数目过大时，设置显示几个数字，其余用省略号（Total number of array elements which trigger summarization rather than full repr (default 1000).）
edgeitems :
int, optional，边缘数目（Number of array items in summary at beginning and end of each dimension (default 3)）.
linewidth :
int, optional，线条宽度 The number of characters per line for the purpose of inserting line breaks (default 75).
suppress :
bool, optional，是否压缩由科学计数法表示的浮点数（Whether or not suppress printing of small floating point values using scientific notation (default False).）
nanstr :
str, optional，String representation of floating point not-a-number (default nan).
infstr :
str, optional，String representation of floating point infinity (default inf).