问题
I am so called newbie in Python. I have difficulties with lists. I have a loop which take some info from textfile and goes through function. If textfiles lenght is 10 rows then output will be 10 separate lists, like that: [0.45] [0.87] ... and so on, for n+1 times(it depends how long textfile is).
How can I put them into single list, like [0.45, 0.87, ...]? I experimented with different loops but nothing :(
I am previously thankfull :) .. and sry about my bad english
Code:
from pyfann import libfann
import os
path="."
ext = ".net"
files = [file for file in os.listdir(path) if file.lower().endswith(ext)]
for j in files:
ann = libfann.neural_net()
ann.create_from_file(j)
print j
f=open('nsltest1.dat','r')
for i in f:
x=i.strip()
y=[float(i) for i in x.split()]
z=ann.run(y)
print z
回答1:
If you have all of your lists stored in a list a,
# a = [[.45], [.87], ...]
import itertools
output = list(itertools.chain(*a))
What makes this answer better than the others is that it neatly joins an arbitrary number of lists together in one line, without a need for a for loop or anything like that.
回答2:
Addition operator + is what you might want.
list1 = [1, 2, 3]
list2 = [4, 5, 6]
merged_list = list1 + list2
print(merged_list) #replace ( and ) with spaces if you're using python 2.x
Will output [1, 2, 3, 4, 5, 6]
回答3:
You might want to have a look at the following questions:
- How to append list to second list (concatenate lists)
- Combining lists into one
- join list of lists in python
Basically, if you're reading your lines in a loop, you can do like
result = []
for line in file:
newlist = some_function(line) # newlist contains the result list for the current line
result = result + newlist
回答4:
You can just add them: [1] + [2] = [1, 2].
来源：https://stackoverflow.com/questions/13481703/merge-different-lists-together-in-python