#!/usr/bin/env python
"""Read files from Maribeth's format into arrays."""
# Needed modules from the standard library
import re
import sys
# Third party modules
import numpy as N
# Code begins
def mwread(fname):
"""Read mw file and return dict with arrays.
The input data is assumed to be in a file whose format is:
r:
0.250029, 0.249549, 0.25019, 0.250232
A:
0.399973, 0.199979, 0.200005, 0.200014
0.199992, 0.400235, 0.200033, 0.200102
B:
0.428502, 0.142868, 0.142897, 0.142838
0.142884, 0.57165, 0.143053, 0.285911
The output is a dict whose keys are the letter labels ('r','A','B', etc)
and whose values are one-dimensional NumPy arrays with the numbers, in
double precision.
:Parameters:
fname : string
Name of the input file."""
fobj = open(fname)
# Regular expression to match array labels
label_re = re.compile('^([a-zA-Z])+:')
# Initialize output dict
dct = {}
# Start the state machine in 'scan' mode and switch to data reading mode
# ('read') whenever we find what looks like a label.
mode = 'scan'
for line in fobj:
if mode == 'scan':
match = label_re.match(line)
if match:
# Switch modes
mode = 'read'
# Prepare state for read mode
name = match.group(1)
data = []
elif mode == 'read':
if line.isspace():
# Pure whitespace lines force a mode switch back to
# scanning for variables
mode = 'scan'
# Store the data that we'd been accumulating for the
# current array
dct[name] = N.array(data,float)
else:
# Read data, assume line contains comma-separated strings
# of numbers
data.extend([float(n) for n in line.split(',')])
# Cleanup before exiting
fobj.close()
return dct
# If run as a script
if __name__ == '__main__':
# This allows calling it from the command line with the name of the file to
# read as an argument
try:
fname = sys.argv[1]
except IndexError:
print 'First argument must be filename to read'
sys.exit(1)
data = mwread(fname)
print 'Data dict:'
for k,val in data.iteritems():
print '%s:' % k
print val
print
# Now, load the names from the data dict as top-level variables (use
# specially named counters just in case the file declares something common
# like 'k'):
for _k,_val in data.iteritems():
exec '%s = _val' % _k
print "Now, you can use either the top-level dict 'data', or the variables:"
print data.keys()
