Ben Keshet a écrit :
I have a probably simple beginner's question -
I have a script that I am currently able to print its output. instead,
i want to write it into a file - I tried different versions of write()
but might have gotten the syntax wrong.
The syntax is:
fileobj.write(something)
Now since you don't say exactly what you tried *and what you got*, we
can't help much more here.
the variable I want to write is
a line from a file I am reading:
"...
f = open('receptor.mol2', 'r')
line = f.readline()[:-1]
If you want to strip the newline characters, you'd better use
line.strip() or line.lstrip()
while '@<TRIPOS>ATOM' not in line:
line = f.readline()[:-1]
#print line
Also, there are simpler ways to iterate over a file:
f = open('somefile.txt')
for line in f:
if '@<TRIPOS>ATOM' in line:
break
print line.lstrip()
f.close()
print random_mol2
..."
e.g. I want to write to a file all the lines in 'receptor.mol2' up to
the string "@<TRIPOS>ATOM" (one after the other). Can anyone please
advice?
The simplest solution for a unix-like command-line program would be to
redirect the standard out to this file, ie:
# python myprog.py destfile.txt
But this may not fit your needs !-)
The other simplest solution is to open the destination file in write (or
append) mode and write to it:
source = open('somefile.txt')
dest = open('otherfile.txt', 'w')
for line in source:
if '@<TRIPOS>ATOM' in line:
break
# we don't strip here, since write doesn't append a newline
dest.write(line)
source.close()
dest.close()
On a related note - how do I read and write to a file that is not in the
same directory?
Give the full absolute or relative path.
e.g how do I provide a pathway to an open command?
source = open('/full/absolute/path/to/my/file.txt')
Note that the exact syntax for a path depends on your os (but the
os.path module can take care of most specificities). The above example
is for a posix system. On Windows, you'll probably have something like:
source = open('C:/full/absolute/path/to/my/file.txt')
HTH
