List and append question

Question

If There are three sentences ,how can I get the every single words of three sentences to be elements in one list ?
Ex) txt file is ..

Learning python is hard
Summer is too hot
Be careful not to be exhusted

Output i want to see is..

['learning','python','is','hard','Summer'...
...'exhusted']

I wrote as follow..

file=open(fname) #three sentences in this file
ans=list()
for line in file:
sline=line.split()
ans.append(sline)
print ans

The result is.. 3 elements having words in each sentence..
Help me out..I spent around 2hours to solve this but I almost give up ..

Answer 1

Solution is as mentioned below:
file=open(fname) #three sentences in this file
ans=list()
for line in file:
sline=line.split()
for word in sline:
ans.append(word)
print ans

You should add another for loop to parse each word in the split line and then append it the list.

Answer 2

Awe. Thank you very much for your help!!