# -*- coding: utf-8 -*-
# coding=UTF-8
# Relational
# Copyright (C) 2010 Salvo "LtWorf" Tomaselli
#
# Relational is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
# Initial readline code from http://www.doughellmann.com/PyMOTW/readline/index.html
import readline
import logging
import os.path
import os
import sys
from relational import relation, parser, rtypes
from termcolor import colored
class SimpleCompleter(object):
'''Handles completion'''
def __init__(self, options):
'''Takes a list of valid completion options'''
self.options = sorted(options)
return
def add_completion(self,option):
'''Adds one string to the list of the valid completion options'''
if option not in self.options:
self.options.append(option)
self.options.sort()
def remove_completion(self,option):
'''Removes one completion from the list of the valid completion options'''
if option in self.options:
self.options.remove(option)
pass
def complete(self, text, state):
response = None
if state == 0:
# This is the first time for this text, so build a match list.
if text:
self.matches =[s
for s in self.options
if s and s.startswith(text)]
#Add the completion for files here
try:
d=os.path.dirname(text)
listf=os.listdir(d)
d+="/"
except:
d=""
listf=os.listdir('.')
for i in listf:
i=(d+i).replace('//','/')
if i.startswith(text):
if os.path.isdir(i):
i=i+"/"
self.matches.append(i)
logging.debug('%s matches: %s', repr(text), self.matches)
else:
self.matches = self.options[:]
logging.debug('(empty input) matches: %s', self.matches)
# Return the state'th item from the match list,
# if we have that many.
try:
response = self.matches[state]
except IndexError:
response = None
logging.debug('complete(%s, %s) => %s',
repr(text), state, repr(response))
return response
relations={}
completer=SimpleCompleter(['SURVEY','LIST','LOAD ','UNLOAD ','HELP ','QUIT','SAVE ','_PRODUCT ','_UNION ','_INTERSECTION ','_DIFFERENCE ','_JOIN ','_LJOIN ','_RJOIN ','_FJOIN ','_PROJECTION ','_RENAME_TO ','_SELECTION ','_RENAME ','_DIVISION '])
def load_relation(filename,defname=None):
if not os.path.isfile(filename):
print >> sys.stderr, colored("%s is not a file" % filename,'red')
return None
f=filename.split('/')
if defname==None:
defname=f[len(f)-1].lower()
if defname.endswith(".csv"): #removes the extension
defname=defname[:-4]
if not rtypes.is_valid_relation_name(defname):
print >> sys.stderr, colored("%s is not a valid relation name" % defname,'red')
return
try:
relations[defname]=relation.relation(filename)
completer.add_completion(defname)
print colored("Loaded relation %s"% defname,'green',attrs=['bold'])
return defname
except Exception, e:
print >>sys.stderr,colored(e,'red')
return None
def survey():
'''performs a survey'''
from relational import maintenance
post= {'software':'Relational algebra (cli)','version':version}
fields=('System','Country','School','Age','How did you find','email (only if you want a reply)','Comments')
for i in fields:
a=raw_input('%s: '%i)
post[i]=a
maintenance.send_survey(post)
def help(command):
'''Prints help on the various functions'''
p=command.split(' ',1)
if len(p)==1:
print 'HELP command'
print 'To execute a query:\n[relation =] query\nIf the 1st part is omitted, the result will be stored in the relation last_.'
print 'To prevent from printing the relation, append a ; to the end of the query.'
print 'To insert relational operators, type _OPNAME, they will be internally replaced with the correct symbol.'
print 'Rember: the tab key is enabled and can be very helpful if you can\'t remember something.'
return
cmd=p[1]
if cmd=='QUIT':
print 'Quits the program'
elif cmd=='LIST':
print "Lists the relations loaded"
elif cmd=='LOAD':
print "LOAD filename [relationame]"
print "Loads a relation into memory"
elif cmd=='UNLOAD':
print "UNLOAD relationame"
print "Unloads a relation from memory"
elif cmd=='SAVE':
print "SAVE filename relationame"
print "Saves a relation in a file"
elif cmd=='HELP':
print "Prints the help on a command"
elif cmd=='SURVEY':
print "Fill and send a survey"
else:
print "Unknown command: %s" %cmd
def exec_line(command):
command=command.strip()
if command.startswith(';'):
return
elif command=='QUIT':
sys.exit(0)
elif command.startswith('HELP'):
help(command)
elif command=='LIST': #Lists all the loaded relations
for i in relations:
if not i.startswith('_'):
print i
elif command=='SURVEY':
survey()
elif command.startswith('LOAD '): #Loads a relation
pars=command.split(' ')
if len(pars)==1:
print colored("Missing parameter",'red')
return
filename=pars[1]
if len(pars)>2:
defname=pars[2]
else:
defname=None
load_relation(filename,defname)
elif command.startswith('UNLOAD '):
pars=command.split(' ')
if len(pars)<2:
print colored("Missing parameter",'red')
return
if pars[1] in relations:
del relations[pars[1]]
completer.remove_completion(pars[1])
else:
print colored("No such relation %s" % pars[1],'red')
pass
elif command.startswith('SAVE '):
pars=command.split(' ')
if len(pars)!=3:
print colored("Missing parameter",'red')
return
filename=pars[1]
defname=pars[2]
if defname not in relations:
print colored("No such relation %s" % defname,'red')
return
try:
relations[defname].save(filename)
except Exception,e:
print colored(e,'red')
else:
exec_query(command)
def replacements(query):
'''This funcion replaces ascii easy operators with the correct ones'''
query=query.replace( '_PRODUCT' , '*')
query=query.replace( '_UNION' , 'ᑌ')
query=query.replace( '_INTERSECTION' , 'ᑎ')
query=query.replace( '_DIFFERENCE' , '-')
query=query.replace( '_JOIN' , 'ᐅᐊ')
query=query.replace( '_LJOIN' , 'ᐅLEFTᐊ')
query=query.replace( '_RJOIN' , 'ᐅRIGHTᐊ')
query=query.replace( '_FJOIN' , 'ᐅFULLᐊ')
query=query.replace( '_PROJECTION' , 'π')
query=query.replace( '_RENAME_TO' , '➡')
query=query.replace( '_SELECTION' , 'σ')
query=query.replace( '_RENAME' , 'ρ')
query=query.replace( '_DIVISION' , '÷')
return query
def exec_query(command):
'''This function executes a query and prints the result on the screen
if the command terminates with ";" the result will not be printed
'''
#If it terminates with ; doesn't print the result
if command.endswith(';'):
command=command[:-1]
printrel=False
else:
printrel=True
#Performs replacements for weird operators
command=replacements(command)
#Finds the name in where to save the query
parts=command.split('=',1)
if len(parts)>1 and rtypes.is_valid_relation_name(parts[0]):
relname=parts[0]
query=parts[1]
else:
relname='last_'
query=command
query=unicode(query,'utf-8')
#Execute query
try:
pyquery=parser.parse(query)
result=eval(pyquery,relations)
print colored("-> query: %s" % pyquery,'green')
if printrel:
print
print result
relations[relname]=result
completer.add_completion(relname)
except Exception, e:
print colored(e,'red')
def main(files=[]):
print colored('> ','blue') + "; Type HELP to get the HELP"
print colored('> ','blue') + "; Completion is activated using the tab (if supported by the terminal)"
for i in files:
load_relation(i)
readline.set_completer(completer.complete)
readline.parse_and_bind('tab: complete')
readline.parse_and_bind('set editing-mode emacs')
readline.set_completer_delims(" ")
while True:
try:
line = raw_input(colored('> ','blue'))
if isinstance(line,str) and len(line)>0:
exec_line(line)
except EOFError:
print
sys.exit(0)
if __name__ == "__main__":
main()