Develop Reference

Concatenate a String and a variable in a .conf file

I wanted to ask how I can concatenate a string and a variable in a .conf file.
Example:
In the settings.conf file:
# The credential is in another, separate passphrase.conf file, declared as 'password'
credential = passphrase/${password}
url = "XYZ.${credential}XYZ.com"
If i do it as shown in my example, I get an error that I have the wrong password, so somehow it is not concatenating correctly.

Check this
import configparser
config = configparser.ConfigParser()
config.read('passphrase.conf')
pass=config['__REPLACE WITH CONFIG SECTION__']['password']
url = "XYZ"+pass+"XYZ.com"

Here is simple way how to concat string and variable.
password_var = 123456
new_string = f"This is my password: {password_var}"
Output:
This is my password: 1234

creating and using a preferences file in python

Brand new to stack and python; hopefully someone wiser than myself can help. I have searched up and down and can't seem to find an actual answer to this, apologies if there is an exact answer and I've missed it :( (the few that I've found are either old or don't seem to work).
Closest I've found is
Best way to retrieve variable values from a text file?
Alas, imp seems to be depreciated and tried figuring out importlib but little above my current brain to figure out how to adapt it as errors throw up left and right on me.
This is very close to what I want and could potentially work if someone can help update with new methods, alas still doesn't have how to overwrite the old variable.
= - - Scenario - - =
I would like to create a preferences file (let's call it settings.txt or settings.py: doesn't need to be cross-compatible with other languages, but some reason I'd prefer txt - any preference/standards coders can impart would be appreciated?).
\\\ settings.txt\
water_type = "Fresh"\
measurement = "Metric"\
colour = "Blue"\
location = "Bottom"\
...
I am creating a script main_menu.py which will read variables in settings.txt and write to this file if changes are 'saved'
ie.
"select water type:"
Fresh
Salt
if water_type is the same as settings.txt, do nothing,
if water_type different, overwrite the variable in the settings.txt file
Other scripts down the line will also read and write to this settings file.
I've seen:
from settings import *
Which seems to work for reading the file if I go the settings.py path but still leaves me on how do I overwrite this.
also open to any better/standard/ideas you guys can think of.
Appreciate any help on this!

Here are some suggestions that may help you:
Use a json file:
settings.json
{
"water_type": "Fresh",
"measurement": "Metric",
"colour": "Blue",
"location": "Bottom",
...
}
then in python:
import json
# Load data from the json file
with open("settings.json", "r") as f:
x = json.load(f) # x is a python dictionary in this case
# Change water_type in x
x["water_type"] = "Salt"
# Save changes
with open("settings.json", "w") as f:
json.dump(x, f, indent=4)
Use a yaml file: (edit: you will need to install pyyaml)
settings.yaml
water_type: Fresh
measurement: Metric
colour: Blue
location: Bottom
...
then in python:
import yaml
# Load data from the yaml file
with open("settings.yaml", "r") as f:
x = yaml.load(f, Loader=yaml.FullLoader) # x is a python dictionary in this case
# Change water_type in x
x["water_type"] = "Salt"
# Save changes
with open("settings.yaml", "w") as f:
yaml.dump(x, f)
Use a INI file:
settings.ini
[Preferences]
water_type=Fresh
measurement=Metric
colour=Blue
location=Bottom
...
then in python:
import configparser
# Load data from the ini file
config = configparser.ConfigParser()
config.read('settings.ini')
# Change water_type in config
config["Preferences"]["water_type"] = "Salt"
# Save changes
with open("settings.ini", "w") as f:
config.write(f)

For .py config files, it's usually static options or settings.
Ex.
# config.py
STRINGTOWRITE01 = "Hello, "
STRINGTOWRITE02 = "World!"
LINEENDING = "\n"
It would be hard to save changes made to the settings in such a format.
I'd recommend a JSON file.
Ex. settings.json
{
"MainSettings": {
"StringToWrite": "Hello, World!"
}
}
To read the settings from this file into a Python Dictionary, you can use this bit of code.
import json # Import pythons JSON library
JSON_FILE = open('settings.json','r').read() # Open the file with read permissions, then read it.
JSON_DATA = json.loads(JSON_FILE) # load the raw text from the file into a json object or dictionary
print(JSON_DATA["MainSettings"]["StringToWrite"]) # Access the 'StringToWrite' variable, just as you would with a dictionary.
To write to the settings.json file you can use this bit of code
import json # import pythons json lib
JSON_FILE = open('settings.json','r').read() # Open the file with read permissions, then read it.
JSON_DATA = json.loads(JSON_FILE) # load the data into a json object or dictionary
print(JSON_DATA["MainSettings"]["StringToWrite"]) # Print out the StringToWrite "variable"
JSON_DATA["MainSettings"]["StringToWrite"] = "Goodnight!" # Change the StringToWrite
JSON_DUMP = json.dumps(JSON_DATA) # Turn the json object or dictionary back into a regular string
JSON_FILE = open('settings.json','w') # Reopen the file, this time with read and write permissions
JSON_FILE.write(JSON_DUMP) # Update our settings file, by overwriting our previous settings
Now, I've written this so that it is as easy as possible to understand what's going on. There are better ways to do this with Python Functions.

You guys are fast! I'm away from the computer for the weekend but had to log in just to say thanks.
I'll look into these more next week when I'm back at it and have some time to give it the attention needed. A quick glance could be a bit of fun to implement and learn a bit more.
Had to answer as adding comment only is on one of your guys solutions and wanted to give a blanket thanks to all!
Cheers

Here's a python library if you choose to do it this way.
If not this is also a good resource.
Creating a preferences file example
Writing preferences to file from python file
import json
# Data to be written
dictionary ={
"name" : "sathiyajith",
"rollno" : 56,
"cgpa" : 8.6,
"phonenumber" : "9976770500"
}
# Serializing json
json_object = json.dumps(dictionary, indent = 4)
# Writing to sample.json
with open("sample.json", "w") as outfile:
outfile.write(json_object)
Reading preferences from .json file in Python
import json
# open and read file content
with open('sample.json') as json_file:
data = json.load(json_file)
# print json file
print(data)

Storing data to a file within a programme

PYTHON
I am making a quiz and at the start I ask for the user to input a username. I want to be able to store the username and a high score that they get or the highest point. But i dont know how to store the username or to save every single one that has been submitted
Please help and be clear. Appreciated.
Thank you

You can use JSON to store the user information.
This is an example of what you may use.
import json
import os
DB_NAME = "db.json"
if not os.path.isfile(DB_NAME):
with open(DB_NAME, "w") as f:
json.dump({},f)
def get_db():
with open(DB_NAME) af f:
return json.load(f)
def write_db(db_dict):
with open(DB_NAME,'w') af f:
json.dump(f,indent=4)
if __name__ == "__main__":
username = raw_input("Username: ")
highscore = int(raw_input("High-score: "))
write_db(get_db()[username] = highscore)
This is the JSON documentation: link
To understand JSON better read this: link

getting error "not all arguments converted during string formatting - Python"

I ma using csv file to fetch some data for automatic login. In my first file, lets call it core.py, i am defining it as function.Here is my code :
import csv
def csvTodict():
dir = os.path.dirname(__file__)
filename = os.path.join(dir, './testdata/InputData.csv')
with open(filename) as f:
logins = dict(filter(None, csv.reader(f)))
return logins
and in another file, i am calling the values for username and password : Its my modules.py
from core import *
fnsignin()
def fnsignin():
try:
myDict=csvTodict()
fnLogin(myDict["Username"],myDict["Password"]
But when i run, I am getting error " not all arguments converted during string formatting". I am not sure where I am doing wrong. Please help

Can't read appended data using pickle.load() method

I have written two scripts Write.py and Read.py.
Write.py opens friends.txt in append mode and takes input for name, email ,phone no and then dumps the dictionary into the file using pickle.dump() method and every thing works fine in this script.
Read.py opens friends.txt in read mode and then loads the contents into dictionary using pickle.load() method and displays the contents of dictionary.
The main problem is in Read.py script, it justs shows the old data, it never shows the appended data ?
Write.py
#!/usr/bin/python
import pickle
ans = "y"
friends={}
file = open("friends.txt", "a")
while ans == "y":
name = raw_input("Enter name : ")
email = raw_input("Enter email : ")
phone = raw_input("Enter Phone no : ")
friends[name] = {"Name": name, "Email": email, "Phone": phone}
ans = raw_input("Do you want to add another record (y/n) ? :")
pickle.dump(friends, file)
file.close()
Read.py
#!/usr/bin/py
import pickle
file = open("friends.txt", "r")
friend = pickle.load(file)
file.close()
for person in friend:
print friend[person]["Name"], "\t", friend[person]["Email"] , "\t", friend[person]["Phone"]
What must be the problem, the code looks fine. Can some one point me in the right direction ?
Thanks.

You have to load from the file several times. Each writing process ignores the others, so it creates a solid block of data independent from the others in the file. If you read it afterwards, it reads only one block at a time. So you could try:
import pickle
friend = {}
with open('friends.txt') as f:
while 1:
try:
friend.update(pickle.load(f))
except EOFError:
break # no more data in the file
for person in friend.values():
print '{Name}\t{Email}\t{Phone}'.format(**person)

You have to call pickle.load once for each time you called pickle.dump. You write routine does not add an entry to the dictionary, it adds another dictionary. You will have to call pickle.load until the entire file is read, but this will give you several dictionaries you would have to merge. The easier way for this would be just to store the values in CSV-format. This is as simple as
with open("friends.txt", "a") as file:
file.write("{0},{1},{2}\n".format(name, email, phone))
To load the values into a dictionary you would do:
with open("friends.txt", "a") as file:
friends = dict((name, (name, email, phone)) for line in file for name, email, phone in line.split(","))