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+--- Thread: "Statement has no effect" (/thread-1769.html)
"Statement has no effect" - birdieman - Jan-25-2017
I am still a beginner, but I want to read a file once, do processing, then write to the file. the read code is:
f = open("test3.txt", "w")
with open("test3.txt", "r") as opened_file:
for line in opened_file:
MS, StartYear, YourStartAge, HerStartAge,
Exempt, BFedItmDed, FedItmDedYrs, State, LivExp,
Inflation, Inf1, Inf2, Inf3, Inf4, Inf5, Inf6, Inf7, Inf8, Inf9, Inf10,
TESTPcnt, TESTYr, TFISTPcnt, TFISTYr, TFESTPcnt, TFESTYr,
TFFISTPcnt, TFFISTYr, TDESTPcnt, TDESTYr, TDFISTPcnt, TDFISTYr,
BTE, BTFI, BTC, TERtn, TFIRtn, TCRtn, BTFE, BTFFI, BTFC, TFERtn,
TFFIRtn, TFCRtn, BTDE, BTDFI, BTDC, TDERtn, TDFIRtn, TDCRtn,
YourJob, SpJob, YourRetInc, SpRetInc, YourSSInc62,
YourSSIncFRA, YourSSInc70, SpSSInc62, SpSSIncFRA, SpSSInc70,
YourRetAge, SpRetAge, YouBgnRetIncAge, SpBgnRetIncAge,
YouSSStartAge, SpSSStartAge, IraStartAge, IraEndAge, IraRequest = line.split()to write the file, I have this code:f.write('{} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {}'
'{} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {}'
'{} {} {} {} {} {} {} {} {} {} {} {} {}'
.format(MS, StartYear, YourStartAge, HerStartAge,
Exempt, BFedItmDed, FedItmDedYrs, State, LivExp,
Inflation, Inf1, Inf2, Inf3, Inf4, Inf5, Inf6, Inf7, Inf8, Inf9, Inf10,
TESTPcnt, TESTYr, TFISTPcnt, TFISTYr, TFESTPcnt, TFESTYr,
TFFISTPcnt, TFFISTYr, TDESTPcnt, TDESTYr, TDFISTPcnt, TDFISTYr,
BTE, BTFI, BTC, TERtn, TFIRtn, TCRtn, BTFE, BTFFI, BTFC, TFERtn,
TFFIRtn, TFCRtn, BTDE, BTDFI, BTDC, TDERtn, TDFIRtn, TDCRtn,
YourJob, SpJob, YourRetInc, SpRetInc, YourSSInc62,
YourSSIncFRA, YourSSInc70, SpSSInc62, SpSSIncFRA, SpSSInc70,
YourRetAge, SpRetAge, YouBgnRetIncAge, SpBgnRetIncAge,
YouSSStartAge, SpSSStartAge, IraStartAge, IraEndAge, IraRequest))
f.close()My PyCharm IDE says the "read" code (highlighting the variables) has no effect. What is wrong with the read code?
RE: "Statement has no effect" - Mekire - Jan-25-2017
You need to go back to string formatting; nevermind file read/writing. Don't do this.
Both the unpacking and formatting code are horrendous.
RE: "Statement has no effect" - birdieman - Jan-25-2017
Thanks for your response, but I am still too new to python to know what your answer means. I had no other idea how to read and write variables to a file.
RE: "Statement has no effect" - metulburr - Jan-25-2017
I would suggest to use JSON rather than relying on line position and splitting delimiters. Which in python is basically a dictionary.
EDIT:
here is an example. Note: this class is using staticmethod to avoid the use of an object, and intends to only handle 1 database due to hardcoding the name in it.
test.py
import sys
import os
import json
class DB:
dirname = 'save'
if not os.path.exists(dirname):
os.mkdir(dirname)
path = os.path.join(dirname, 'database{}'.format(sys.version.split()[0]))
@staticmethod
def load():
data = open(DB.path)
obj = json.load(data)
data.close()
return obj
@staticmethod
def save(obj):
f = open(DB.path, 'w')
f.write(json.dumps(obj))
f.close()Output:metulburr@ubuntu:~$ cd save
bash: cd: save: No such file or directoryOutput:metulburr@ubuntu:~$ python
Python 2.7.12 (default, Nov 19 2016, 06:48:10)
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from test import DB
>>> data = {
...
... 'entry1':1,
... 'entry2':2
... }
>>> data
{'entry2': 2, 'entry1': 1}
>>> DB.save(data)
>>> exit()Output:metulburr@ubuntu:~$ cat save/database2.7.12
{"entry2": 2, "entry1": 1}Output:metulburr@ubuntu:~$ python
Python 2.7.12 (default, Nov 19 2016, 06:48:10)
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from test import DB
>>> d = DB.load()
>>> d
{u'entry2': 2, u'entry1': 1}RE: "Statement has no effect" - Mekire - Jan-25-2017
Well, I would rather see something like this (untested):
But really as Metul said you should, at bare minimum, probably be using JSON. Honestly it kinda looks like you should be using an actual database.
RE: "Statement has no effect" - snippsat - Jan-25-2017
There are also easy solution for fast storage as i show in tutorial with dataset.
It's just a couple of lines connet(make database),
now trow a Python dictionary into the table and we are finish.
Have now a fully working database,that also can be outputted as json.
RE: "Statement has no effect" - birdieman - Jan-25-2017
Thanks to all for responding.
Metalburr-
I still have a lot to learn regarding your example.
When it says "entry1:1" I assume the "entry1" (the key) is my variable name, and I assume the "1" is the value of that variable. Is that correct?
How/where do I load the database for the first time, like {MS: M, StartYear: 2017, ........}
RE: "Statement has no effect" - metulburr - Jan-25-2017
Quote:When it says "entry1:1" I assume the "entry1" (the key) is my variable name, and I assume the "1" is the value of that variable. Is that correct?Yes
Quote:How/where do I load the database for the first time, like {MS: M, StartYear: 2017, ........}The easiest method would be to write it in JSON (dictionary) format in the first place.
RE: "Statement has no effect" - Kebap - Jan-25-2017
Do you create this file yourself? Can you change the format?
RE: "Statement has no effect" - birdieman - Jan-25-2017
yes, i can change the format. After reading Metulburr, and if I understand dictionaries correctly, I would have to refer to my variables like xyz["StartYear"] and I do not want to do that -- too long and cumbersome. I just want to use my variables by their name, like StartYear (if possible).
Do you have another suggestion?