using cPickle

[leegeorg07]

hi im trying to expand on my dictionary learning and i currently have two problems with this code:

import cPickle
file = open('phonebook.txt', 'w')

phonebook = {'Andrew Parson':8806336, \
'Emily Everett':6784346, 'Peter Power':7658344, \
'Lewis Lame':1122345}

cPickle.dump(phonebook,file)

raw_input("press enter to show how to add a key and a value")

phonebook['Ginger' ] = 1234567

cPickle.dump(phonebook,file)

print phonebook

p = float(raw_input("do you want to add a new person? (1 = yes, 0 = no)"))
s = float(raw_input("do you want to stay? (again 1 = yes, 0 = no)"))
if s == 1:
    if p == 1:
        n = raw_input("what is the persons name?")
        nb = raw_input("what is there number?")
        phonebook[n] = nb
        cPickle.dump(phonebook,file)
        v = float(raw_input("do you want to see the phonebook now? (1 = yes, 0 = no)"))
        if v == 1:
              print phonebook
        else:
            print "thank you for using a George Lee program"
            raw_input("press enter to close")

    else:
        print "thank you for using a George Lee program"
        raw_input("press enter to close")
else:
    print "thank you for using a George Lee program"
    raw_input("press enter to close")

print "thank you for using a George Lee program"
g =  float(raw_input("are you sure you want to go? (again 1 = yes, 0 = no)"))
if g == 0:
    if p == 1:
        n = raw_input("what is the persons name?")
        nb = raw_input("what is there number?")
        phonebook[n] = nb
        cPickle.dump(phonebook,file)
        v = float(raw_input("do you want to see the phonebook now? (1 = yes, 0 = no)"))
        if v == 1:
              print phonebook
        else:
            print "thank you for using a George Lee program"
            raw_input("press enter to close")

    else:
        print "thank you for using a George Lee program"
        raw_input("press enter to close")

file.close()

first of all how can i make the txt file (phonebook.txt) easily readable?
secondly how can i edit the code so that it uses phonebook.txt as the dictionary phonebook
any help and advice welcome thanks

[Gribouillis]

If you want to store the notebook in a readable form, a good solution could be pretty-print the dictionary to the file without using the cPickle module. You would have two functions

from pprint import pprint
TXTFILE = "notebook.txt"

def dump_notebook(notebook):
  fout = open(TXTFILE, "w")
  pprint(notebook, fout)
  fout.close()

def load_notebook():
  fin = open(TXTFILE, "r")
  dic = eval(fin.read())
  fin.close()
  return dic

Also you could structure your program like this

def user_interaction(notebook):
  ... # raw inputs and user requests

def main():
  notebook = load_notebook()
  try:
    user_interaction(notebook)
  finally:
    dump_notebook(notebook)

main()

With this structure, you would be sure that the notebook is save to the file when the program exits, even if something fails in the interaction with the user.

[sneekula]

Actually the module shelve works better with dictionaries:

# save and retrieve data via a shelve byte stream file
# creates a 'persistent to file' dictionary

import shelve

phonebook = {
'Andrew Parson': 8806336,
'Emily Everett': 6784346, 
'Peter Power': 7658344,
'Lewis Lame': 1122345
}

# dictionary data will be in a shelve byte stream file
shlv2 = shelve.open('phonebook.slv')

phonebook['Ginger Roger'] = 1234567

# this will save all current phonebook data 
# access key will "phone_dict"
shlv2["phone_dict"] = phonebook

phonebook['Larry Lark'] = 9234568

# you can update again before you close
shlv2["phone_dict"] = phonebook
shlv2.close()

print '-'*50

# testing ...
# this could be a second program ...
# retrieve the saved data from the file
shlv3 = shelve.open('phonebook.slv')
#print shlv3.keys()
# use the access key "phone_dict"
# notice that this loads right into a dictionary
phonebook2 = shlv3["phone_dict"]
print phonebook2

print '-'*50

print phonebook2['Lewis Lame']
print phonebook2['Larry Lark']
print phonebook2['Ginger Roger']

shlv3.close()

[leegeorg07]

thanks for the posts and griboullis' idea seems easier but i dont really understand the def function :( (i kind of skipped that part) so could you explain them and also possibly explain the prettyprint module

[Gribouillis]

If you don't understand well the def (function definitions) in python, I suggest that you read this http://www.openbookproject.net/thinkCSpy/ch03.xhtml.

About the functions I wrote above, I defined 4 functions
* dump_notebook(notebook), which takes a dictionary argument, and pretty-prints the dictionary in the file notebook.txt when it is called.
*load_notebook() which reads the file notebook.txt (assumed to contain a dictionary. Initially, you could put just {} in that file) and evaluates the content of this file to obtain a python dictionary object, which is returned.
*user_interaction(notebook) The body of this function should contain all that you need in order to interact with the user during the execution of the program (the raw_input's, the modification of the content of the dictionary). You don't need the file during this function. You just use the dictionary object
*main() A main function which, when called, loads the notebook from the file, calls user_interaction, and finally dumps the (possibly modified) dictionary to the file.

main() is called as the last statement of the program. I hope this explains a little :)

[leegeorg07]

thanks i understand it better now but the document will me called phonebook.txt and also if possible could you show me how i could incorporate it into my existing code (my first post)

[leegeorg07]

thanks for the pm griboullis but im having a bit of trouble

this is my code:

from pprint import pprint
TXTFILE = "phonebook.txt"

def dump_notebook(phonebook):
  fout = open(TXTFILE, "w")
  pprint(notebook, fout)
  fout.close()

def load_notebook():
  fin = open(TXTFILE, "r")
  dic = eval(fin.read())
  fin.close()
  return dic

def user_interaction(phonebook):
phonebook = {'Andrew Parson':8806336, \
'Emily Everett':6784346, 'Peter Power':7658344, \
'Lewis Lame':1122345}

raw_input("press enter to show how to add a key and a value")

phonebook['Ginger' ] = 1234567

print phonebook

p = float(raw_input("do you want to add a new person? (1 = yes, 0 = no)"))
s = float(raw_input("do you want to stay? (again 1 = yes, 0 = no)"))
if s == 1:
    if p == 1:
        n = raw_input("what is the persons name?")
        nb = raw_input("what is there number?")
        phonebook[n] = nb
        v = float(raw_input("do you want to see the phonebook now? (1 = yes, 0 = no)"))
        if v == 1:
              print phonebook
        else:
            print "thank you for using a George Lee program"
            raw_input("press enter to close")

    else:
        print "thank you for using a George Lee program"
        raw_input("press enter to close")
else:
    print "thank you for using a George Lee program"
    raw_input("press enter to close")

print "thank you for using a George Lee program"
g =  float(raw_input("are you sure you want to go? (again 1 = yes, 0 = no)"))
if g == 0:
    if p == 1:
        n = raw_input("what is the persons name?")
        nb = raw_input("what is there number?")
        phonebook[n] = nb
        v = float(raw_input("do you want to see the phonebook now? (1 = yes, 0 = no)"))
        if v == 1:
              print phonebook
        else:
            print "thank you for using a George Lee program"
            raw_input("press enter to close")

    else:
        print "thank you for using a George Lee program"
        raw_input("press enter to close")

def main():
    notebook = load_phonebook()
    try:
        user_interaction(phonebook)
    finally:
        dump_phonebook(phonebook)

main()

when i run it nothing happens. how can i fix this

[Gribouillis]

first replace ALL the occurences of notebook by phonebook. Then the code you put in the function user_interaction must be INDENTED (like in a if statement). Also you should drop the initial assignment phonebook = {...} . Insted, you could put the part {...} in an initial phonebook.txt file.
Next: use your head, and python's error messages!