New default relation's format is csv, as defined in RFC4180

git-svn-id: http://galileo.dmi.unict.it/svn/relational/trunk@67 014f5005-505e-4b48-8d0a-63407b615a7c

CHANGELOG

@@ -48,3 +48,5 @@
 
 0.8
 - Added __eq__ to relation object, will compare ignoring order.
+- New default relation's format is csv, as defined in RFC4180
+- Converted sample's relations to csv

maingui.py

@@ -89,16 +89,16 @@ class Ui_Form(object):
             if i != "__builtins__":
                 self.lstRelations.addItem(i)
     def saveRelation(self):
-	  filename = QtGui.QFileDialog.getSaveFileName(self.Form,QtGui.QApplication.translate("Form", "Save Relation"),"",QtGui.QApplication.translate("Form", "Relations (*.tlb)"))
+      filename = QtGui.QFileDialog.getSaveFileName(self.Form,QtGui.QApplication.translate("Form", "Save Relation"),"",QtGui.QApplication.translate("Form", "Relations (*.csv)"))
       
       filename=str(filename.toUtf8()) #Converts QString to string
       if (len(filename)==0):#Returns if no file was selected
         return
-	  if (not filename.endswith(".tlb")):#Adds extension if needed
+      if (not filename.endswith(".csv")):#Adds extension if needed
-	    filename+=".tlb"
+        filename+=".csv"
       
       for i in self.lstRelations.selectedItems():
-			self.relations[str(i.text().toUtf8())].save(filename)
+            self.relations[str(i.text().toUtf8())].save(filename,use_csv)
       return
     def unloadRelation(self):
         for i in self.lstRelations.selectedItems():
@@ -120,13 +120,20 @@ class Ui_Form(object):
 
     def loadRelation(self):
         #Asking for file to load
-		filename = QtGui.QFileDialog.getOpenFileName(None,QtGui.QApplication.translate("Form", "Load Relation"),"",QtGui.QApplication.translate("Form", "Relations (*.tlb);;Text Files (*.txt);;All Files (*)"))
+        filename = QtGui.QFileDialog.getOpenFileName(None,QtGui.QApplication.translate("Form", "Load Relation"),"",QtGui.QApplication.translate("Form", "Relations (*.csv);;Old Relations (*.tlb);;Text Files (*.txt);;All Files (*)"))
         
         #Default relation's name
         f=str(filename.toUtf8()).split(os.sep) #Split the full path
         defname=f[len(f)-1].lower() #Takes only the lowercase filename
         
-		if (defname.endswith(".tlb")): #removes the extension
+        use_csv=True
+        
+        if defname.endswith(".tlb"):
+            defname=defname[:-4]
+            use_csv=False #Old format, not using csv
+            
+        
+        if (defname.endswith(".csv")): #removes the extension
             defname=defname[:-4]
         
         res=QtGui.QInputDialog.getText(self.Form, QtGui.QApplication.translate("Form", "New relation"),QtGui.QApplication.translate("Form", "Insert the name for the new relation"),
@@ -134,7 +141,7 @@ class Ui_Form(object):
         if res[1]==False:
             return
         
-		self.relations[str(res[0].toUtf8())]=relation.relation(filename)
+        self.relations[str(res[0].toUtf8())]=relation.relation(filename,use_csv)
         self.updateRelations()
     
     def addProduct(self):

relation.py

@@ -17,21 +17,35 @@
 # author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
 
 from rtypes import *
+import csv
 
 class relation (object):
     '''This objects defines a relation (as a group of consistent tuples) and operations
     A relation can be represented using a table
     Calling an operation and providing a non relation parameter when it is expected will
     result in a None value'''    
-    def __init__(self,filename=""):
+    def __init__(self,filename="",comma_separated=True):
         '''Creates a relation, accepts a filename and then it will load the relation from
         that file. If no parameter is supplied an empty relation is created. Empty
-        relations are used in internal operations'''
+        relations are used in internal operations.
+        By default the file will be handled like a comma separated as described in
+        RFC4180, but it can also be handled like a space separated file (previous
+        default format) setting to false the 2nd parameter.
+        The old format is deprecated since it doesn't permit fields
+        with spaces, you should avoid using it.'''
         if len(filename)==0:#Empty relation
             self.content=[]
             self.header=header([])
             return
+        #Opening file
         fp=file(filename)
+        if comma_separated:
+            reader=csv.reader(fp) #Creating a csv reader
+            self.header=header(reader.next()) # read 1st line
+            self.content=[]
+            for i in reader.__iter__(): #Iterating rows
+                self.content.append(i)
+        else: #Old format
             self.header=header(fp.readline().replace("\n","").strip().split(" "))
         
             self.content=[]
@@ -39,20 +53,38 @@ class relation (object):
             while len(row)!=0:#Reads the content of the relation
                 self.content.append(row.replace("\n","").strip().split(" "))
                 row=fp.readline()
+        
+        #Closing file
         fp.close()
         
     
-    def save(self,filename):
+    def save(self,filename,comma_separated=True):
-        '''Saves the relation in a file'''
+        '''Saves the relation in a file. By default will save using the csv
+        format as defined in RFC4180, but setting comma_separated to False,
+        it will use the old format with space separated values.
+        The old format is deprecated since it doesn't permit fields
+        with spaces, you should avoid using it.'''
+        
+        fp=file(filename,'w') #Opening file in write mode
+        if comma_separated:
+            writer=csv.writer(fp) #Creating csv writer
+            
+            #It wants an iterable containing iterables
+            head=[]
+            head.append(self.header.attributes)
+            writer.writerows(head)
+            
+            #Writing content, already in the correct format
+            writer.writerows(self.content)
+        else:
             res=""
             res+=" ".join(self.header.attributes)
             
             for r in self.content:
                 res+="\n"
                 res+=" ".join(r)
-        fp=file(filename,'w')
             fp.write(res)
-        fp.close()
+        fp.close() #Closing file
     def rearrange(self,other):
         '''If two relations share the same attributes in a different order, this method
         will use projection to make them have the same attributes' order.

samples/dates.csv

@@ -0,0 +1,6 @@
+"date"
+"2008-12-12"
+"2007-08-12"
+"1985-05-09"
+"1988-4-21"
+"1992-7-27"

samples/person_room.csv

@@ -0,0 +1,9 @@
+"id","room"
+"0","1"
+"1","4"
+"2","2"
+"3","2"
+"4","5"
+"5","1"
+"6","5"
+"7","1"

samples/rooms.csv

@@ -0,0 +1,9 @@
+"room","phone"
+"0","1515"
+"1","1516"
+"2","1617"
+"3","1601"
+"4","1041"
+"5","9212"
+"6","1424"
+"7","1294"

samples/skills.csv

@@ -0,0 +1,18 @@
+"id","skill"
+"0","C"
+"0","Python"
+"1","Python"
+"1","C++"
+"1","System Admin"
+"2","C"
+"2","PHP"
+"3","C++"
+"4","C++"
+"4","C"
+"4","Perl"
+"5","Perl"
+"5","C"
+"7","Python"
+"7","C"
+"7","PHP"
+"9","Java"