学习笔记5—Python 将多维数据转为一维数组 （总结）

<code class="language-python">import operator  
from functools import reduce  
a = [[1,2,3], [4,6], [7,8,9,8]]  
print(reduce(operator.add, a))  
[1, 2, 3, 4, 6, 7, 8, 9, 8]</code>        

a = [[1,2,3], [5, 8], [7,8,9]]
l=[]
for m in range(0,3):
for i in a[m]:
l.append(i)
print(l)
[1, 2, 3, 5, 8, 7, 8, 9]      

from itertools import chain
b=[[1,2,3], [5,8], [7,8,9]]
c=list(chain(*b))
print(c)
[1, 2, 3, 5, 8, 7, 8, 9]
a=[[1,2,3], [5,8], [7,8,9]]
a= eval（'['+str(a).replace(' ','').replace('[','').replace(']','')+']')
print(a)
[1, 2, 3, 5, 8, 7, 8, 9]
 

def flatten(a):
if not isinstance(a, (list, )):
return [a]
else:
b = []
for item in a:
b += flatten(item)
return b
if __name__ == '__main__':
a = [[[1,2],3],[4,[5,6]],[7,8,9]]
print(flatten(a))
[1, 2, 3, 4, 5, 6, 7, 8, 9]
 

ab = [[1,2,3], [5,8], [7,8,9]]
print([i for item in ab for i in item])
[1, 2, 3, 5, 8, 7, 8, 9]      

2、矩阵转数组：data = [[1,2,3,]] 去掉外层----> data = data[0,:]--->[1,2,3]

3、数组：data = [[1],[2]] ---> data = data.flatten() ---> [1,2]