Develop Reference

Adding and saving to list in external json file

I'm very new to Python and I'm struggling when it comes to saving the data that the user has entered to a json file when quitting the application. Also every time I run my code all the data inside the json file is wiped. When I enter the input to save and exit I get this error code:
Traceback (most recent call last):
File "C:\Users\User\Downloads\sit_resources\sit_resources\sit_admin_application.py", line 86, in <module>
main_menu()
File "C:\Users\User\Downloads\sit_resources\sit_resources\sit_admin_application.py", line 23, in main_menu
save()
File "C:\Users\User\Downloads\sit_resources\sit_resources\sit_admin_application.py", line 82, in save
patients_file.write(finallist)
io.UnsupportedOperation: not writable
Here is my code below:
import json
patients_file = open("patients.json", "r")
loaded_patients = json.load(patients_file)
def main_menu():
'''Function docstring documentation here'''
print("\nSIT Data Entry Menu")
print("==========================")
print("1: Print Patients' List\n2: Add Patient\n3: Delete Patient\n4: Exit")
print("==========================")
input1 = input("Enter your menu selection:")
if input1 == "1":
patients_list()
elif input1 == "2":
add_patient()
elif input1 == "3":
remove_patient()
elif input1 == "4":
save()
else:
print ("Please enter a valid input")
main_menu()
def patients_list():
print("\nSIT current patients:\n")
loaded_patients.sort(key=str.casefold)
for number, item in enumerate(loaded_patients, start=1):
print(number, item)
print("\nTotal number of registered patients is", len(loaded_patients))
main_menu()
def add_patient():
newpatient = input("\nEnter new Patient -> Lastname Firstname:")
print ("Do the details you have entered look correct? y/n")
confirm = input()
if confirm == "y":
loaded_patients.append(newpatient)
print ("Patient successfully added to list")
main_menu()
elif confirm == "n":
print ("Patient import cancelled")
add_patient()
else:
print ("Please enter a valid input")
add_patient()
def remove_patient():
print ("Which of the following patients would you like to remove?")
loaded_patients.sort(key=str.casefold)
for number, item in enumerate(loaded_patients, start=1):
print(number, item)
try:
removepatient = int(input("\nEnter the number of the patient you would like to remove"))
print ("Does the patient number you have entered look correct? y/n")
delconfirm = input()
if delconfirm == "y":
try:
removepatient = (removepatient - 1)
loaded_patients.pop(removepatient)
print ("Patient was successfully removed from the list")
main_menu()
except IndexError:
print("Please enter a valid input")
remove_patient()
elif delconfirm == "n":
print ("Deletion cancelled")
remove_patient()
else:
print ("Please enter a valid input")
remove_patient()
except ValueError:
print ("Please enter a valid input")
remove_patient()
def save():
open("patients.json", "w")
finallist = json.dumps(loaded_patients)
patients_file.write(finallist)
print("Patient List successfully saved")
quit()
main_menu()
I store the json file in the same directory and all it contains is a list:
["Soreback Leigh", "Neckache Annette", "Sorefoot Jo", "Kaputknee Matt", "Brokentoe Susan", "Tornligament Alex"]
If anyone could help me out and let me know what I'm doing wrong or any simpler method I could use, it would be greatly appreciated.
Thanks

Your code has several issues, including the one you're asking about.
The main thing is the overall structure: your code keeps calling functions from functions, never really returning - that can work for a very long time, but in the end it will fail, and it's not the correct way to go about this.
Take for example your main_menu() - once an option is selected, you call the function matching it, and when the work there is done, you call main_menu() again. However, a better way to do the same:
def main_menu():
choice = ''
while choice != '4':
print('some options, 4 being "save and quit"')
if choice == 1:
patients_list()
...
# no if choice == 4: save() here, we'll save at the end
save()
This way, the menu will keep getting printed when you return to it, but every function that is executed, is allowed to return and then the loop restarts, unless option 4 was entered. And since you can allow the functions to return, no need to call main_menu() at the end of them.
Your save() function has some issues: it doesn't need quit() any more, but you also didn't do anything with the file you opened. A nice way to do this in Python is to use a 'context manager', which boils down to using with, like this:
def save():
with open("patients.json", "w") as patients_file:
finallist = json.dumps(loaded_patients)
patients_file.write(finallist)
That's assuming your loaded_patients always contains all the current patients of course. Given that's what it is for, you should consider just calling it patients.
Your file only contains a list, because a list is what you are creating in those functions and a list is a valid content for a json file. If you expected a dictionary, you should construct one in the rest of the code, but from your example it's unclear what exactly you would expect that dictionary to look like.

The conventional way to load and save json:
with open('patients.json', 'r') as f:
loaded_patients = json.load(f)
with open('patients.json', 'w') as f:
json.dump(loaded_patients, f)

You are trying to write to patients_file, which you opened in read-only mode.

Python pickles not storing data

I am trying to create a registrar system through Python with pickles. I have gotten the system to record user input, but it does not save it for future implementations of the program.
Here is the code that will start the program:
import datetime
import pandas as pd
import pickle as pck
import pathlib
from pathlib import *
from registrar import *
prompt = "Please select an option: \n 1 Create a new course \n 2 Schedule a new course offering \n 3 List this school's course catalogue \n 4 List this school's course schedule \n 5 Hire an instructor \n 6 Assign an instructor to a course \n 7 Enroll a student \n 8 Register a student for a course \n 9 List this school's enrolled students \n 10 List the students that are registered for a course \n 11 Submit a student's grade \n 12 Get student records \n 13 Exit"
farewell = "Thank you for using the Universal University Registrar System. Goodbye!"
print ("Welcome to the Universal University Registration System.")
print ("\n")
try: #As long as CTRL-C has not been pressed, or 13 not been input by user.
input_invalid = True
while input_invalid:
inst = input("Please enter the name of your institution. ").strip()
domain = input("Please enter the domain. ").strip().lower()
if inst == "" or domain == "":
print("Your entry is invalid. Try again.")
else:
input_invalid = False
schoolie = Institution(inst, domain)
if Path(inst + '.pkl').exists() == False:
with open(inst + '.pkl', 'r+b') as iptschool:
schoolie = pck.load(iptschool)
while True:
print (prompt)
user_input = input("Please enter your choice: ")
try:
user_input = int(user_input)
if user_input < 1 or user_input > 14: #UserInput 14: on prompt.
raise ValueError("Please enter a number between 1 and 13, as indicated in the menu.")
except ValueError:
print("Not a valid number. Please try again.")
if user_input == 1: #Create a new course
input_invalid2 = True #Ensure that the user actually provides the input.
while input_invalid2:
input_name = input("Please enter a course name: ").strip()
input_department = input("Please enter the course's department: ").strip()
input_number = input("Please enter the course's number (just the number, not the departmental prefix): ").strip()
try:
input_number = int(input_number)
except ValueError:
print ("Please print an integer. Try again.")
input_credits = input("Please enter the number of credits awarded for passing this course. Please use an integer: ").strip()
try:
input_credits = int(input_credits)
except ValueError:
print ("Please print an integer. Try again.")
if input_name != "" and input_department != "" and input_number and input_credits:
input_invalid2 = False #Valid input
else:
print("One or more of your entries is invalid. Try again.")
added_course = Course(input_name, input_department, input_number, input_credits)
for course in schoolie.course_catalog:
if course.department == input_department and course.number == input_number and course.name == input_name:
print("That course is already in the system. Try again.")
input_invalid2 == True
if input_invalid2 == False:
schoolie.add_course(added_course)
print ("You have added course %s %s: %s, worth %d credits."%(input_department,input_number,input_name, input_credits))
And here is the second option, which SHOULD reveal that it is stored, but it does not.
elif user_input == 2: #Schedule a course offering
input_invalid2 = True #Ensure that the user actually provides the input.
while input_invalid2:
input_department = input("Please input the course's department: ").strip()
input_number = input("Please input the course's number: ").strip()
course = None
courseFound = False
for c in schoolie.course_catalog:
if c.department == input_department and c.number == input_number: #Course found in records
courseFound = True
course = c
input_section_number = input("Please enter a section number for this course offering: ").strip()
input_instructor = input("If you would like, please enter an instructor for this course offering: ").strip()
input_year = input("Please enter a year for this course offering: ").strip()
input_quarter = input("Please enter the quarter in which this course offering will be held - either SPRING, SUMMER, FALL, or WINTER: ").strip().upper()
if input_course != "" and input_course in schoolie.course_catalog and input_section_number.isdigit() and input_year.isdigit() and input_quarter in ['SPRING', 'SUMMER', 'FALL', 'WINTER'] and input_credits.isdigit():
if input_instructor != "": #Instructor to be added later, if user chooses option 6.
added_course_offering = CourseOffering(c, input_section_number, None, input_year, input_quarter)
else:
added_course_offering = CourseOffering(c, input_section_number, input_instructor, input_year, input_quarter)
schoolie.add_course_offering(added_course_offering)
input_invalid2 = False #Valid input
print ("You have added course %s, Section %d: %s, worth %d credits."%(input_course,input_section_number,input_name, input_credits))
else:
print("One or more of your entries is invalid. Try again.")
if courseFound == False: #If course has not been found at the end of the loop:
print("The course is not in our system. Please create it before you add an offering.")
break
By the way, I think I have the system closing properly. Correct me if I'm wrong:
elif user_input == 13: #Exit
with open(inst + '.pkl', 'wb') as output:
pck.dump(schoolie, output, pck.HIGHEST_PROTOCOL)
del schoolie
print (farewell)
sys.exit()
except KeyboardInterrupt: #user pushes Ctrl-C to end the program
print(farewell)
I believe that there is something wrong with the way that I am setting up the pickles files. I'm creating them, but I seem not to be putting data into them.
I apologize for the long-winded nature of this question, but I hope that the details will help you understand the problems that I've been having. Thanks in advance for the help!

it seems you may have dump and load reversed: (from the docs)
Signature: pck.load(file, *, fix_imports=True, encoding='ASCII', errors='strict')
Docstring:
Read and return an object from the pickle data stored in a file.
Signature: pck.dump(obj, file, protocol=None, *, fix_imports=True)
Docstring:
Write a pickled representation of obj to the open file object file.

With all those lines of code, it does get a little confusing, but I don't see any code that is pickling and writing the objects to a file.
Before anything else, you should assign the file to a variable so you can reference it. To do this, you'll have code similar to this:MyFile = open("FileName.extension","wb"). MyFile can be any name you want, it will be what you use later to reference the file. FileName is the name of the file itself. This is the name it will have in File Explorer. .extension is the file's extension, specifying the type of file. You should use .dat for this. wb is the file access mode. "w" means write, and "b" means binary. (Pickled objects can only be stored in a binary file.)
To write the pickled objects, you'll need this code:pck.dump(object,MyFile). (Usually, you would use pickle.dump(object,MyFile), but you imported pickle as pck.)
After writing the data to the file, you'll want to retrieve it. To do this, the "wb" instance of MyFile needs to be closed like this:MyFile.close(). Then you'll need to re-open the file in read mode using the following code:MyFile = open("FileName.extension","rb") Then you would use this:object = pickle.load(MyFile) to read the data. In the preceding example, (the load function), your object must have the same name as when you pickled it using the dump function. (pck.dump(object,MyFile))
In the end, you'll end up with something similar to this:
if writing conditions are true:
MyFile = open("FileName.dat","wb")
pickle.dump(object,MyFile) # This will be repeated for each object.
MyFile.close()
if reading conditions are true:
MyFile = open("FileName.dat","rb")
object = pickle.load(MyFile) # This will be repeated for each object.
MyFile.close()
I'm sorry if this wasn't the answer you wanted. Because of all those lines of code, it is somewhat hard to understand. I need clarification to give a better answer.

(Python) How to test if a string is contained in a file

I'm trying to create a username database and the code all runs how I want except for when I try to test if the file contains the entered text. For some reason it just runs past the elif statement and hits the else statement if it already exists in the text.
Here is the full code:
class username:
def add():
while(True):
file = open("usernames.txt", 'r+')
names = list(file.read())
entered = str(input("Username: "))
if len(entered) == 0:
print("Please enter a valid username\n")
continue
elif not(entered.isalpha):
print("Please enter a valid username\n")
continue
elif entered in file.read():
print("That name is already in use.",
"\nPlease enter a different username. \n")
continue
elif len(entered) < 4 or len(entered) > 12:
print("Please enter a username with 4-12 characters.\n")
continue
else:
print(entered)
file.close()
add = open("usernames.txt", 'a+')
plusnewline = entered + "\n"
add.write(plusnewline)
add.close()
break
def list():
file = open("usernames.txt","r+")
names = file.read()
print(names)
file.close()
username.add()
username.list()
edit: Answered by Shadow:
Changed:
names = list(file.read())
to:
names = file.read()
and changed:
elif entered in file.read():
to:
elif entered in names:

You can only call file.read once - after that it's already read.
Either use file.seek(0) to go back to the start of the file (which will allow you to read it again), or cache the contents in a variable so that you can reuse it (that is, refer to your names variable)

reading, writing, appending, and deleting files in python

here's my code, i could use your help.
My program is supposed to accept data input, create new text files,read and write into text files, append text into already existing text files, truncate and delete files.
Now the problem i have with my program is that the the part of the code that is supposed to append text, truncate the content of a text file and delete a text file is not working and the program does not return any errors during run time.
import os
from sys import argv
filename = argv
def menu():
holder = input("enter 1 to create new file or 2 to use existing ones\n")
if holder == 1:
dam = raw_input("Enter name of new text file:\n")+'.txt'
textfile = open(dam, 'w+')
happ = raw_input("\nPlease enter record into your new file\n\n")
textfile.write(happ)
textfile.close()
print "*******************"
print "*******************\n"
print "To view the content of your new file, enter 'yes' otherwise enter 'no' to exit"
gett = raw_input()
if gett == 'yes':
print "*******************"
print "\nyour inputted record is>>>\n"
display = open(dam)
print(display.read())
print'\n'
menu()
elif gett == 'no':
print ("\nOk, see you later. Have a nice day!")
print'\n'
menu()
else:
print "\nyou have entered a wrong input"
print '\n'
menu()
elif holder == 2:
filename = raw_input("Enter name of file:\n")+'.txt'
entry = raw_input("Press 7 to append text into this file, 8 to truncate the content of this file, or 9 to delete this file : ")
if entry == 7:
print ("Displayed below is the content of your file, continue to append more text at the bottom of the file.(text is limited to 3 lines)\n")
textfiles = open(filename, 'a+')
print (textfiles.read())
line1 = raw_input( )
line2 = raw_input( )
line3 = raw_input( )
print "\nSaving..."
textfiles.write(line1)
textfiles.write('\n')
textfiles.write(line2)
textfiles.write('\n')
textfiles.write(line3)
textfiles.write('\n')
print "\nSaved!"
textfiles.close()
elif entry == 8:
textfiles = open(filename, 'w')
print "Truncating the file..."
textfiles.truncate()
print "Done, truncated."
textfiles.close()
right = raw_input("Do you want to write into this file? Y/N : ")
if right == 'Y':
textfiles = open(filename, 'a+')
print "text is limited to 3 lines"
line1 = raw_input('\n')
line2 = raw_input()
line3 = raw_input()
print "\nSaving..."
textfiles.write(line1)
textfiles.write('\n')
textfiles.write(line2)
textfiles.write('\n')
textfiles.write(line3)
textfiles.write('\n')
print "\nSaved!"
textfiles.close()
else:
print "Ok have a nice day"
elif entry == 9:
print "Deleting the file..."
try:
os.remove(filename)
except OSError, e: #if failed, report it back to the user
print ("Error: %s - %s." % (e.filename, e.strerror))
print "Done, deleted."
else:
print "Error! wrong entry"
print '\n'
menu()
else:
print "\nyou have entered a wrong input"
print '\n'
menu()
menu()
This is the output it gives
enter 1 to create new file or 2 to use existing ones
2
Enter name of file:
test
Press 7 to append text into this file, 8 to truncate the content of this file, or 9 to delete this file : 8
Error! wrong entry
enter 1 to create new file or 2 to use existing ones
ANY HELP ON HOW TO MAKE THIS WORK?

You are using the function raw_input() for your variable entry at the line
entry = raw_input("Press 7 to append text into this file, 8 to truncate the content of this file, or 9 to delete this file : ")
Refering to the documentation of python2 (https://docs.python.org/2/library/functions.html#raw_input), the function raw_input return a String.
After, you are testing your variable entry against integer values. Since a String never equals an int, the test won't work. And your code fall in the last condition block which is "wrong input"
To fix this issue, you should use the input function like you did at the begining of your code (https://docs.python.org/2/library/functions.html#input):
entry = input("Press 7 to append text into this file, 8 to truncate the content of this file, or 9 to delete this file : ")
or cast entry to int
entry = int(raw_input("Press 7 to append text into this file, 8 to truncate the content of this file, or 9 to delete this file : "))

How to write "No file ends with" a user-defined extension

I was wondering if there was a way to tell the user that no file in a directory they specified has the file extension they are looking for. The only way I could think of uses an if/else, but would be tripped up if any other file extension exists in the directory. I was able to find something but it was bash: Listing files in a directory that do not end with vXXX and not exactly what I was looking for.
Here is an example of a directory:
out-30000000.txt.processed
out-31000000.txt.processed
out-32000000.txt.processed
out-33000000.txt.processed
out-34000000.txt.processed
nope.csv
If I use the following code:
def folder_location():
location = raw_input("What is the folder containing the data you like processed located? ")
#location = "C:/Code/Samples/Dates/2015-06-07/Large-Scale Data Parsing/Data Files"
if os.path.exists(location) == True: #Tests to see if user entered a valid path
print "You entered:",location
if raw_input("Is this correct? Use 'Y' or 'N' to answer. ") == "Y":
print ""
file_extension(location)
else:
folder_location()
else:
print "I'm sorry, but the file location you have entered does not exist. Please try again."
folder_location()
def file_extension(location):
file_extension = raw_input("What is the file type (.txt for example)? ")
print "You entered:", file_extension
if raw_input("Is this correct? Use 'Y' or 'N' to answer. ") == "Y":
print ""
each_file(location, file_extension)
else:
file_extension(location)
def each_file(location, file_extension):
try:
column = (raw_input("Please enter column name you want to analyze: ")) #Using smcn
print "You entered:",column
if raw_input("Is this correct? Use 'Y' and 'N' to answer. ") == "Y":
print ""
sort_by(location,file_extension,column)
else:
each_file(location,file_extension)
except TypeError:
print "That is not a valid column name. Please try again."
each_file(location,file_extension)
def sort_by(location, file_extension, column):
content = os.listdir(location)
for item in content:
if item.endswith(file_extension):
data = csv.reader(open(os.path.join(location,item)),delimiter=',')
col_position = get_columnposition(data.next(),column)
to_count = sorted(data, key=operator.itemgetter(col_position))
count_date(to_count, location)
else:
print "No file in this directory ends with " + file_extension
I get:
No file in this directory ends with .processed
and then the rest of my output (code not posted here).
Is there a way for me to say (I'm going to put it in a code block just to show how it works in my mind):
def file_extension(location):
file_extension = raw_input("What is the file type (.txt for example)? ")
print "You entered:", file_extension
if raw_input("Is this correct? Use 'Y' or 'N' to answer. ") == "Y":
print ""
each_file(location, file_extension)
else:
file_extension(location)
def each_file(location, file_extension):
try:
column = (raw_input("Please enter column name you want to analyze: ")) #Using smcn
print "You entered:",column
if raw_input("Is this correct? Use 'Y' and 'N' to answer. ") == "Y":
print ""
sort_by(location,file_extension,column)
else:
each_file(location,file_extension)
except TypeError:
print "That is not a valid column name. Please try again."
each_file(location,file_extension)
def sort_by(location, file_extension, column):
content = os.listdir(location)
for item in content:
if item.endswith(file_extension):
data = csv.reader(open(os.path.join(location,item)),delimiter=',')
col_position = get_columnposition(data.next(),column)
to_count = sorted(data, key=operator.itemgetter(col_position))
count_date(to_count, location)
if no item.endswith(file_extension):
print "No file in this directory ends with " + file_extension
Any help would be greatly appreciated. If it would help, I could edit in the rest of my code I have at the moment.
Thanks!

Your logic should be the following:
Ask for the directory
Ask for the extension
Check if any file ends with that extension
If there is at least one file, then ask for the column
To make all this easier, use csv and glob:
import glob
import csv
import os
directory = input('Please enter the directory: ')
extension = input('Please enter the extension (.txt, .csv): ')
files = list(glob.glob(os.path.join(directory, extension)))
if not files:
print('Sorry, no files match your extension {} in the directory {}'.
format(extension, directory))
else:
for file_name in files:
col = input('Enter the column number for {}'.format(file_name))
with open(file_name, 'r') as thefile:
reader = csv.reader(thefile, delimiter=',')
for row in reader:
try:
do_something(row[col])
except IndexError:
print('Column {} does not exist'.format(col))