如何在Python中将4个列表合并为1个

Question

my code is like

testGraph=open(input("Enter a file name:"))
for line in testGraph:
  temp=line.split()

and the out put is like

['0', '1']
['2', '1']
['0', '2']
['1', '3']

and I want to make them into

[['0', '1'],['2', '1'],['0', '2'],['1', '3']]

could someone help me?

Answer 1

You can use itertools.chain() to flat lists into one list.

>>> cmd = ['ls', '/tmp']
>>> numbers = range(3)
>>> itertools.chain(cmd, numbers, ['foo', 'bar'])
<itertools.chain object at 0x0000000003943F28>
>>> list(itertools.chain(cmd, numbers, ['foo', 'bar']))
['ls', '/tmp', 0, 1, 2, 'foo', 'bar']

But if you want to have a list of lists, then appending to the list would be your choice.

testGraph=open(input("Enter a file name:"))
result = []
for line in testGraph:
  result.append(line.split())

Answer 2

List comprehension , works for you,

testGraph = open(input("Enter a file name:")) 
result = [line.split() for line in testGraph]

Execution:

In [29]: testGraph = open('abc.txt')

In [30]: [line.split() for line in testGraph]
Out[30]: [['0', '1'], ['2', '1'], ['0', '2'], ['1', '3']]

Answer 3

This should work with minimal change to your code. temp will then have the combined list you want.

testGraph=open(input("Enter a file name:"))
temp = []
for line in testGraph:
  temp.append(line.split())