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UnboundLocalError - Python Error

I am getting the following error with my code:
UnboundLocalError: local variable 'row' referenced before assignment
I have tried many things, but nothing has worked. I suspect it is something to do around the 'quantityQuestion' subprogram. According to the scripter, the problem is at line 97.
import csv
import sys
global totalPrice
totalPrice = 0
addItem = ""
gtinNum = ""
quantity = 0
restart = ""
global receipt
receipt = open("receipt.txt", "w+")
global restockTxt
restockTxt = open("restock.txt", "w+")
global price
price = 0
global file2
file2 = open("ChocolateCSV2.csv", "r")
global file2w
file2w = open("ChocolateCSV2.csv", "w", newline="")
def restart():
restart = input("Would you like to restart? Y/N")
if restart.lower() == "y":
actionQ()
else:
print("Exiting program.")
file2.close()
sys.exit()
def priceSub(): #Defining the restart subprogram
priceQ = input("Would you like to add an item? Y/N") #Asks the user if they would like to add an item.
global totalPrice #Declaring totalPrice and making it global.
totalPrice = int(price) + totalPrice #Setting totalPrice to add the variable price to itself.
if priceQ.lower() == "y": #If statement that checks to see if the user has entered a "y".
gtinQuestion() #If it is true, it will start the gtinQuestion subprogram.
else: #Anything other than a "y" will do the following commands.
global receiptCont #Declaring the receipt content as a global variable.
receiptCont = receipt.read() #Reads the receipt.
receipt.close() #Closes the file.
print(receiptCont) #Prints the content of the receipt.
print("Total Price: " + "%.2f" % round(totalPrice, 2)) #Prints the totalPrice variable rounded to two decimal places.
restart()
def quantityQuestion(): #Defining the subprogram for the quantity.
quantity = input("How much would you like?") #Asks the user how much of the item they would like.
if quantity.isdigit() == False: #If statement to check whether or not the user has entered an integer or not.
quantityQuestion() #If they have not entered an integer, it will ask the question again.
global price #Declaring the variable price as a global variable.
price = "" #Setting price to an empty string.
reader = csv.reader(file2, delimiter = ",")
csvList = list(reader)
for row in csvList: #Loop that seperates each row in the CSV
if str(gtinNum) in row: #If statement to check if the GTIN given by the user is in the CSV.
receipt.write(str(row) + "\n") #If it is in one of the CSV rows, it will write the row to the text file.
receipt.write(str("- Quantity: " + quantity + "\n")) #It also writes the quantity given by the user.
price = float(row[2]) * int(quantity) #The price is the price given by the CSV file multiplied by the quantity.
receipt.write("- Price: " + str("%.2f" % round(price, 2)) + "\n") #The final price (after the multiplication) is written to the text file also.
row[2] = row[2] - quantity
writeCSV = csv.writer(file2w)
writeCSV.writerow(row)
file2w.close()
priceSub() #Starts the restart subprogram.
break #Breaks the loop.
else:
print("The code entered could not be found - Please re-enter") #If it is not in the CSV it will print this error message.
gtinQuestion() #Starts the gtinQuestion subprogram.
def gtinQuestion(): #Defining the gtinQuestion subprogram.
global gtinNum #Declaring the gtinNum variable as global.
gtinNum = input("Please enter the GTIN-8 Code of the product you would like to order:") #Setting that variable to the initial question.
if gtinNum.isdigit() == False or len(gtinNum) != 8: #If the code given is not an integer or is not 8 digits long...
print("Please re-enter your GTIN-8 code - Reason: Invalid Code") #It will print this error message and ask the question again.
gtinQuestion()
elif gtinNum.isdigit() == True and len(gtinNum) == 8: #If it is an integer and is 8 digits long...
quantityQuestion() #It will start the quantityQuestion subprogram.
def restockAction():
reader = csv.reader(file2, delimiter = ",")
csvList = list(reader)
for row in csvList:
stDiff = float(row[5]) - float(row[3])
if float(row[3]) <= float(row[4]):
restockTxt.write(row[0]+" | "+row[1]+" | "+"Stock Replenished: "+(str(stDiff)+"\n"))
restockTxt.close()
row[3] = row[5]
writeCSV = csv.writer(file2w)
writeCSV.writerows(csvList)
file2w.close()
else:
if float(row[3]) >= float(row[4]):
restockTxt.write("No (other) stock needs to be replenished.")
restockTxt.close()
restockRead = open("restock.txt", "r")
print(restockRead.read())
restart()
def actionQ():
restock = input("What action would you like to perform?:\n Restock (Enter 1)\n Order (Enter 2)")
if restock == "1" or restock == "restock":
print("Restock Action Requested...")
restockAction()
elif restock == "2" or restock == "order":
print("Ordering action Requested...")
gtinQuestion()
else:
actionQ()
actionQ()
Any help is appreciated,
Thanks.

The problem is in restockAction():
for row in csvList:
# some code
else:
if float(row[3]) >= float(row[4]):
# ^
If there are no rows in csvList, row will not have any value, since the for will not be executed, but the else block will be executed.
So row in the else block of the for has yet to defined.
Did you intend to attach the else to the if, not the for:
for row in csvList:
stDiff = float(row[5]) - float(row[3])
if float(row[3]) <= float(row[4]):
# ...
else:
# ...

You have to verify you have that you have any rows before checking whether row[index] has a value:
else:
if row and float(row[3]) >= float(row[4]):
restockTxt.write("No (other) stock needs to be replenished.")
restockTxt.close()
restockRead = open("restock.txt", "r")
print(restockRead.read())
restart()
if row and ... acts as a vanguard, protecting the interpreter from executing row[index]. If row is None, if row == False and it returns immediately without evaluating the rest of the statement.

Having trouble with creating a variable that adds to itself

I have a variable in my code (named totalPrice) which will set itself to a price given and then when the user adds a product to their list it will add that price to totalPrice. However, when running it, it resets the variable to 0. I believe it has something to do with the placement of it as I have placed it inside a subprogram. I do not know what to do with it as I can't seem to find a place for it.
My code is as follows:
import csv
import sys
import re
import os
addItem = ""
gtinNum = ""
quantity = 0
restart = ""
f = open("ChocolateCSV.csv", "rt")
global receipt
receipt = open("receipt.txt", "w+")
def restart():
restart = input("Would you like to restart? Y/N")
if restart.lower() == "y":
gtinQuestion()
else:
global receiptCont
receiptCont = receipt.read()
receipt.close()
print(receiptCont)
print("Total Price: " + "%.2f" % round(totalPrice, 2))
sys.exit()
def quantityQuestion():
quantity = input("How much would you like?")
if quantity.isdigit() == False:
quantityQuestion()
global price
price = ""
global totalPrice
totalPrice = 0
with open("ChocolateCSV.csv", 'r') as file2:
for row in csv.reader(file2):
if str(gtinNum) in row:
receipt.write(str(row) + "\n")
receipt.write(str("- Quantity: " + quantity + "\n"))
price = float(row[2]) * int(quantity)
totalPrice += price
receipt.write("- Price: " + str("%.2f" % round(price, 2)) + "\n")
restart()
break
def gtinQuestion():
global gtinNum
gtinNum = input("Please enter the GTIN-8 Code of the product you would like to order:")
if gtinNum.isdigit() == False or len(gtinNum) != 8:
gtinQuestion()
elif gtinNum.isdigit() == True and len(gtinNum) == 8:
quantityQuestion()
gtinQuestion()

totalPrice is not global within restart().
also think of re-designing your code, there's a lot of dangerous recursion and global variables. E.g. if quantity.isdigit() == False: within quantityQuestion calls quantityQuestion and continues despite the error with the computation.
The whole point of having functions is to hide computation and variables inside. Use function parameters etc and learn clean python (try import this within a python console).

python: Adding to username

I am fairly new to python and I need to make a program to ask 10 questions, save the score into a file and allow someone to read the scores in from the file.
My problem: I need to check if the person who has done the quiz already has a record in the file, and if so, I need to add their score to the end of their record.
The records should look like this:
name,score,score,score,score,
etc so they can be split using commas.
I am also looking for the simplest answer, not the most efficient. Also, if you could comment the code, it would make it much easier. Here is my code so far:
import random
import math
import operator as op
import sys
import re
def test():
num1 = random.randint(1, 10)
num2 = random.randint(1, num1)
ops = {
'+': op.add,
'-': op.sub,
'*': op.mul,
}
keys = list(ops.keys())
rand_key = random.choice(keys)
operation = ops[rand_key]
correct_result = operation(num1, num2)
print ("What is {} {} {}?".format(num1, rand_key, num2))
while True:
try:
user_answer = int(input("Your answer: "))
except ValueError:
print("Only enter numbers!")
continue
else:
break
if user_answer != correct_result:
print ("Incorrect. The right answer is {}".format(correct_result))
return False
else:
print("Correct!")
return True
print("1. Are you a student?")
print("2. Are you a teacher?")
print("3. Exit")
while True:
try:
status = int(input("Please select an option:"))
except ValueError:
print("Please enter a number!")
else:
if status not in {1,2,3}:
print("Please enter a number in {1,2,3}!")
else:
break
if status == 1:
username=input("What is your name?")
while not re.match("^[A-Za-z ]*$", username) or username=="":
username=input(str("Please enter a valid name (it must not contain numbers or symbols)."))
print ("Hi {}! Wellcome to the Arithmetic quiz...".format(username))
while True:
try:
users_class = int(input("Which class are you in? (1,2 or 3)"))
except ValueError:
print("Please enter a number!")
else:
if users_class not in {1,2,3}:
print("Please enter a number in {1,2,3}!")
else:
break
correct_answers = 0
num_questions = 10
for i in range(num_questions):
if test():
correct_answers +=1
print("{}: You got {}/{} {} correct.".format(username, correct_answers, num_questions,
'question' if (correct_answers==1) else 'questions'))
if users_class == 1:
class1 = open("Class1.txt", "a+")
newRecord = username+ "," + str(correct_answers) + "," + "\n"
class1.write(newRecord)
class1.close()
elif users_class == 2:
class2 = open("Class2.txt", "a+")
newRecord = username+ "," + str(correct_answers) + "," + "\n"
class2.write(newRecord)
class2.close()
elif users_class == 3:
class3 = open("Class3.txt", "a+")
newRecord = username+ "," + str(correct_answers) + "," + "\n"
class3.write(newRecord)
class3.close()
else:
print("Sorry, we can not save your data as the class you entered is not valid.")

EDIT:
Add this function before your "test" function:
def writeUserScore(file, name, score):
with open (file, "r") as myfile:
s = myfile.read()
rows = s.split("\n")
data = {}
for row in rows:
tmp = row.split(",")
if len(tmp) >= 2: data[tmp[0]] = tmp[1:]
if name not in data:
data[name] = []
data[name].append(str(score))
output = ""
for name in data:
output = output + name + "," + ",".join(data[name]) + "\n"
handle = open(file, "w+")
handle.write(output)
handle.close()
After that, where you have "if users_class == 1:" do this:
writeUserScore("Class1.txt", username, str(correct_answers))
Do the same for the other two else ifs.
Let me know what you think!
Try using a dictionary to hold the existing file data.
Read the file in a variable called "str" for example. And then do something like this:
rows = str.split("\n")
data1 = {}
for row in rows:
tmp = row.split(",")
data1[tmp[0]] = tmp[1:]
When you have a new score you should then do:
if username not in data1:
data1[username] = []
data1[username] = str(correct_answers)
And to save the data back to the file:
output = ""
for name in data1:
output = outupt + name + "," + ",".join(data1[name]) | "\n"
And save the contents of "output" to the file.
PS: If you are not bound by the file format you can use a JSON file. I can tell you more about this if you wish.
Hope that helps,
Alex

First, define these functions:
from collections import defaultdict
def read_scores(users_class):
"""
If the score file for users_class does not exist, return an empty
defaultdict(list). If the score file does exist, read it in and return
it as a defaultdict(list). The keys of the dict are the user names,
and the values are lists of ints (the scores for each user)
"""
assert 0 <= users_class <= 3
result = defaultdict(list)
try:
lines =open("Class%d.txt"%users_class,'r').readlines()
except IOError:
return result
for line in lines:
# this line requires python3
user, *scores = line.strip().split(',')
# if you need to use python2, replace the above line
# with these two lines:
# line = line.strip().split(',')
# user, scores = line[0], line[1:]
result[user] = [int(s) for s in scores]
return result
def write_scores(users_class, all_scores):
"""
Write user scores to the appropriate file.
users_class is the class number, all scores is a dict kind of dict
returned by read_scores.
"""
f = open("Class%d.txt"%users_class,'w')
for user, scores in all_scores.items():
f.write("%s,%s\n"%(user, ','.join([str(s) for s in scores])))
def update_user_score(users_class, user_name, new_score):
"""
Update the appropriate score file for users_class.
Append new_score to user_name's existing scores. If the user has
no scores, a new record is created for them.
"""
scores = read_scores(users_class)
scores[user_name].append(new_score)
write_scores(users_class, scores)
Now, in the last portion of your code (where you actually write the scores out) becomes much simpler. Here's an example of writing some scores:
update_user_score(1, 'phil', 7)
update_user_score(1, 'phil', 6)
update_user_score(1, 'alice', 6)
update_user_score(1, 'phil', 9)
there will be two lines in Class1.txt:
phil,7,6,9
alice,6
We read the whole file into a dict (actually a defaultdict(list)),
and overwrite that same file with an updated dict. By using defaultdict(list), we don't have to worry about distinguishing between updating and adding a record.
Note also that we don't need separate if/elif cases to read/write the files. "Scores%d.txt"%users_class gives us the name of the file.

Python return function not working for me

I have the following code:
#gets the filename from the user
b= input("Please enter a file name to be opened: ")
a = (b+".txt")
#main data storage and other boolean options
data =[]
result1 =[]
on = True
#File reading in main body with try and except functionality.
try:
check = open(a, 'r')
line =check.readlines()
for items in line:
breakup= items.split()
number, salary, position, first, oname1, oname2, last = breakup
data.append(tuple([last, first + ' ' + oname1 + ' ' + oname2, number, position, salary]))
except IOError as e :
print("Failed to open", fileName)
#Employee creation function, takes the line and stores it in the correct position.
def employee_creation():
result = [((item[0] +", "+ item[1]).ljust(30), int(item[2]), item[3].ljust(15), int(item[4])) for item in data]
for items in result:
result1.append((items[0][0:30], format(items[1], "^5d"), items[2][0:15], "£"+format((items[3]),"<8d")))
return(result)
employee_creation()
print(result)
while on == True:
print("Please select what option you would like to use to search for employees:")
option = int(input("""
1 - Salary (X to X)
2 - Job Titlle
3 - Name, Payroll Number
:"""))
if option == 1:
start = input("What range would you like to start from: ")
end = input("What is the maximum range you would like :")
for items in result:
print(items[3])
if items[3]>start and items[3]<end:
print(items)
else:
print("No employees with this information can be found")
on= False
else:
on= False
However my def employee_creation() doesn't actually return result. I need it to make it a global variable so that I can use it to launch personal querys against the data.
Can anyone see why its not working?

No need to use the evil global variables. You forgot to store the result of your function to another variable.
def employee_creation():
result = [((item[0] +", "+ item[1]).ljust(30), int(item[2]), item[3].ljust(15), int(item[4])) for item in data]
for items in result:
result1.append((items[0][0:30], format(items[1], "^5d"), items[2][0:15], "£"+format((items[3]),"<8d")))
return result # no need for () here
result = employee_creation() # store the return value of your function
print(result)

How can I end while loop and skip for loop?

How do I make it where if the user enters 'no' the program won't go through the for loop either. I don't want it to tmpfile.write(line) if the user enters 'no'.
def remove():
coname = raw_input('What company do you want to remove? ') # company name
f = open('codilist.txt')
tmpfile = open('codilist.tmp', 'w')
for line in f:
if coname.upper() in line:
while True:
answer = raw_input('Are you sure you want to remove ' + line.upper() + '?')
if answer == 'yes':
print line.upper() + '...has been removed.'
elif answer == 'no':
break # HERE IS WHERE I NEED HELP
else:
print 'Please choose yes or no.'
else:
tmpfile.write(line)
else:
print 'Company name is not listed.'
f.close()
tmpfile.close()
os.rename('codilist.tmp', 'codilist.txt')

Set a flag variable and then break out of the while loop. Then in the for loop, check if the flag is set, and then break.
PS: if is not a loop

The easiest way to do this is to create a function that gets user input:
def get_yes_or_no(message):
while True:
user_in = raw_input(message).lower()
if user_in in ("yes", "no"):
return user_in
And modify your original function like so:
def remove():
coname = raw_input('What company do you want to remove? ') # company name
f = open('codilist.txt')
tmpfile = open('codilist.tmp', 'w')
for line in f:
if coname.upper() in line:
answer = get_yes_or_no('Are you sure you want to remove ' + line.upper() + '?')
#answer logic goes here
else:
tmpfile.write(line)
else:
print 'Company name is not listed.'
f.close()
tmpfile.close()
os.rename('codilist.tmp', 'codilist.txt')

Python has exceptions, which you can use in place of a GOTO type of construction.
class Breakout(Exception):
pass
def remove():
coname = raw_input('What company do you want to remove? ') # company name
f = open('codilist.txt')
tmpfile = open('codilist.tmp', 'w')
try:
for line in f:
if coname.upper() in line:
while True:
answer = raw_input('Are you sure you want to remove ' + line.upper() + '?')
if answer == 'yes':
print line.upper() + '...has been removed.'
elif answer == 'no':
raise Breakout()
else:
print 'Please choose yes or no.'
else:
tmpfile.write(line)
else:
print 'Company name is not listed.'
except Breakout:
pass
f.close()
tmpfile.close()
os.rename('codilist.tmp', 'codilist.txt')
Notice where in exception is raised in the middle there.

You have to put the whole for loop in a function and use return to get out of it:
def find_and_remove(f,coname,tmpfile):
for line in f:
if coname.upper() in line:
while True:
answer = raw_input('Are you sure you want to remove ' + line.upper() + '?')
if answer == 'yes':
print line.upper() + '...has been removed.'
elif answer == 'no':
return # HERE IS WHERE I NEED HELP
else:
print 'Please choose yes or no.'
else:
tmpfile.write(line)
else:
print 'Company name is not listed.'
def remove():
coname = raw_input('What company do you want to remove? ') # company name
f = open('codilist.txt')
tmpfile = open('codilist.tmp', 'w')
find_and_remove(f,coname,tmpfile)
f.close()
tmpfile.close()
os.rename('codilist.tmp', 'codilist.txt')

Instead of using an infinite loop and breaking when you skip a line, differentiate between the three cases (skip, remove, and invalid answer) using a flag in the loop condition. You set the flag to exit the loop in the skip case, break in the remove case, and leave the flag as-is in the invalid answer case. This lets you use the else clause of the while (which is triggered if the while exits because the condition became false) to detect the skip case. From there, you can jump ahead to the next iteration of the for loop using continue (or skip all the rest of the lines using break - it isn't quite clear from the question which you intend, but the difference is change of keyword):
for line in f:
if coname.upper() in line:
answered = False
while not answered:
answer = raw_input('Are you sure you want to remove ' + line.upper() + '?')
if answer == 'yes':
print line.upper() + '...has been removed.'
break
elif answer == 'no':
answered = True # HERE IS WHERE I NEED HELP
else:
print 'Please choose yes or no.'
else:
continue
else:
tmpfile.write(line)
else:
print 'Company name is not listed.'