Tim Chase wrote:
I would like to extract values corresponding to variable DIHED (here
4660.1650) and getting also the mean value from all DIHED.
To just pull the DIHED values, you can use this:
import re
find_dihed_re = re.compile(r'\bDIHED\s*=\s*([.-e\d]+)', re.I)
total = count = 0
for line in file('file.txt'):
m = find_dihed_re.search(line)
if m:
str_value = m.group(1)
try:
f = float(str_value)
total += f
count += 1
except:
print "Not a float: %s" % str_value
print "Total:", total
print "Count:", count
if count:
print "Average:", total/count
If you want a general parser for the file, it takes a bit more work.
Just because I was a little bored:
import re
pair_re = re.compile(r'\b([^=:]+)\s*[=:]\s*([-.e\d]+)', re.I)
def builder(fname='file.txt'):
thing = {}
for line in file(fname):
if not line.strip(): continue
line = line.upper()
if 'NSTEP' in line: # 1
# it's a new thing # 1
if thing: # 1
yield thing # 1
thing = {} # 1
thing.update(dict(
(k.strip(), float(v))
for k,v in pair_re.findall(line)
))
#if 'EWALD' in line: # 2
# # it's a new thing # 2
# if thing: # 2
# yield thing # 2
# thing = {} # 2
if thing:
yield thing
# average the various values to demo
total = count = 0
for thing in builder():
total += thing.get('DIHED', 0)
count += 1
print "Total:", total
print "Count:", count
if count:
print "Average:", total/count
This makes a more generic parser (comment/uncomment the
corresponding "# 1" or "# 2" code based on whether a new block is
found by a first line containing "NSTEP" or a last line
containing "EWALD"). This yields a dictionary for each item in
the input file. You can pull out whichever value(s) you want to
manipulate.
-tkc
--
http://mail.python.org/mailman/listinfo/python-list
