[HowTo] Unicode strings and checking the type of a variable

Jython 2.7
(used in SikuliX version 1.1.0+ on Java 7+) directly supports unicode strings

Jython 2.5
(used in SikuliX versions prior to 1.1.0 or with 1.1.0 on Java 6) needs special treatment of strings, depending on wether they contain only ascii characters (x00 .. xFF) or not

---------------- some examples

# check wether a variable contains unicode text
def isUnicode(var):
  if isinstance(var, unicode):
    return True
  elif isinstance(var, str):
    return False
  else:
    raise Exception("isUnicode: not unicode nor string: %s" % var)

# check wether a variable contains is list
def isList(var):
  if isinstance(var, list):
    return True
  else:
    return False

# a list of unicode strings
uList = [u"xyz", u"abc"]
print "uList is", uList
print "uList is a list", isList(uList)

# a list of plain ascii strings
sList = ["xyz", "abc"]
print "sList is", sList
print "sList is a list", isList(sList)

# a unicode string variable
uVar = uList[0]
print "uList[0] =", uVar
print "uVar is a list", isList(uVar)

# a plain ascii variable
sVar = sList[0]
print "sList[0]", sVar
print "sVar is a list", isList(sVar)

# a plain ascii variable from unicode string
# crashes if string not only contains ascii characters (x00 .. xFF)
sVar = str(uList[0])
print "str(uList[0])", sVar

# SikuliX feature, to print a mix of unicode and ascii variables
# needed, when running with Jython 2.5
uprint("use of uprint", uVar, sVar)

# check type and convert
# str(someUnicode) will crash if non-ascii chars present
print "isUnicode(uVar)", isUnicode(uVar)
print "isUnicode(str(uVar))", isUnicode(str(uVar))
print "isUnicode(sVar)", isUnicode(sVar)
print "isUnicode(unicode(sVar))", isUnicode(unicode(sVar))
try:
  print "isUnicode(uList)", isUnicode(uList)
except:
  print "not unicode nor string:\n%s" % uList

# example with real unicode characters
uVar = "漢字"
# this crashes with Jython 2.5 (use uprint)
print "real unicode:", uVar