pyqtgraph/configfile.py
2012-04-04 22:54:46 -04:00

201 lines
6.0 KiB
Python

# -*- coding: utf-8 -*-
"""
configfile.py - Human-readable text configuration file library
Copyright 2010 Luke Campagnola
Distributed under MIT/X11 license. See license.txt for more infomation.
Used for reading and writing dictionary objects to a python-like configuration
file format. Data structures may be nested and contain any data type as long
as it can be converted to/from a string using repr and eval.
"""
import re, os, sys
from collections import OrderedDict
GLOBAL_PATH = None # so not thread safe.
import units
class ParseError(Exception):
def __init__(self, message, lineNum, line, fileName=None):
self.lineNum = lineNum
self.line = line
#self.message = message
self.fileName = fileName
Exception.__init__(self, message)
def __str__(self):
if self.fileName is None:
msg = "Error parsing string at line %d:\n" % self.lineNum
else:
msg = "Error parsing config file '%s' at line %d:\n" % (self.fileName, self.lineNum)
msg += "%s\n%s" % (self.line, self.message)
return msg
#raise Exception()
def writeConfigFile(data, fname):
s = genString(data)
fd = open(fname, 'w')
fd.write(s)
fd.close()
def readConfigFile(fname):
#cwd = os.getcwd()
global GLOBAL_PATH
if GLOBAL_PATH is not None:
fname2 = os.path.join(GLOBAL_PATH, fname)
if os.path.exists(fname2):
fname = fname2
GLOBAL_PATH = os.path.dirname(os.path.abspath(fname))
try:
#os.chdir(newDir) ## bad.
fd = open(fname)
s = unicode(fd.read(), 'UTF-8')
fd.close()
s = s.replace("\r\n", "\n")
s = s.replace("\r", "\n")
data = parseString(s)[1]
except ParseError:
sys.exc_info()[1].fileName = fname
raise
except:
print "Error while reading config file %s:"% fname
raise
#finally:
#os.chdir(cwd)
return data
def appendConfigFile(data, fname):
s = genString(data)
fd = open(fname, 'a')
fd.write(s)
fd.close()
def genString(data, indent=''):
s = ''
for k in data:
sk = str(k)
if len(sk) == 0:
print data
raise Exception('blank dict keys not allowed (see data above)')
if sk[0] == ' ' or ':' in sk:
print data
raise Exception('dict keys must not contain ":" or start with spaces [offending key is "%s"]' % sk)
if isinstance(data[k], dict):
s += indent + sk + ':\n'
s += genString(data[k], indent + ' ')
else:
s += indent + sk + ': ' + repr(data[k]) + '\n'
return s
def parseString(lines, start=0):
data = OrderedDict()
if isinstance(lines, basestring):
lines = lines.split('\n')
lines = filter(lambda l: re.search(r'\S', l) and not re.match(r'\s*#', l), lines) ## remove empty lines
indent = measureIndent(lines[start])
ln = start - 1
try:
while True:
ln += 1
#print ln
if ln >= len(lines):
break
l = lines[ln]
## Skip blank lines or lines starting with #
if re.match(r'\s*#', l) or not re.search(r'\S', l):
continue
## Measure line indentation, make sure it is correct for this level
lineInd = measureIndent(l)
if lineInd < indent:
ln -= 1
break
if lineInd > indent:
#print lineInd, indent
raise ParseError('Indentation is incorrect. Expected %d, got %d' % (indent, lineInd), ln+1, l)
if ':' not in l:
raise ParseError('Missing colon', ln+1, l)
(k, p, v) = l.partition(':')
k = k.strip()
v = v.strip()
## set up local variables to use for eval
local = units.allUnits.copy()
local['OrderedDict'] = OrderedDict
local['readConfigFile'] = readConfigFile
if len(k) < 1:
raise ParseError('Missing name preceding colon', ln+1, l)
if k[0] == '(' and k[-1] == ')': ## If the key looks like a tuple, try evaluating it.
try:
k1 = eval(k, local)
if type(k1) is tuple:
k = k1
except:
pass
if re.search(r'\S', v) and v[0] != '#': ## eval the value
try:
val = eval(v, local)
except:
ex = sys.exc_info()[1]
raise ParseError("Error evaluating expression '%s': [%s: %s]" % (v, ex.__class__.__name__, str(ex)), (ln+1), l)
else:
if ln+1 >= len(lines) or measureIndent(lines[ln+1]) <= indent:
#print "blank dict"
val = {}
else:
#print "Going deeper..", ln+1
(ln, val) = parseString(lines, start=ln+1)
data[k] = val
#print k, repr(val)
except ParseError:
raise
except:
ex = sys.exc_info()[1]
raise ParseError("%s: %s" % (ex.__class__.__name__, str(ex)), ln+1, l)
#print "Returning shallower..", ln+1
return (ln, data)
def measureIndent(s):
n = 0
while n < len(s) and s[n] == ' ':
n += 1
return n
if __name__ == '__main__':
import tempfile
fn = tempfile.mktemp()
tf = open(fn, 'w')
cf = """
key: 'value'
key2: ##comment
##comment
key21: 'value' ## comment
##comment
key22: [1,2,3]
key23: 234 #comment
"""
tf.write(cf)
tf.close()
print "=== Test:==="
num = 1
for line in cf.split('\n'):
print "%02d %s" % (num, line)
num += 1
print cf
print "============"
data = readConfigFile(fn)
print data
os.remove(fn)