Develop Reference

Add \n to the last element of a list, in a list of lists

So I have an external file where each line has a task formatted like this:
User, Title of task, Description of task, Date assigned, Due date, Completed (Yes/No)
I have created a list of lists where within the main list are lists of the line above essentially where each element is separated from the ", ".
So it looks like this:
[['User', 'Title of task', 'Description of task', 'Date assigned', 'Due Date', 'Completed (Yes/No)']]
I am trying to change the last element of the last list to include "\n" at the end.
Here is the code I implemented:
with open('tasks.txt', 'w') as f2:
count = 0
for i in list_of_tasks:
count += 1
if count == len(list_of_tasks):
list_of_tasks[i][-1] = str(f"{list_of_tasks[i][-1]}\n")
f2.write(", ".join(i))
else:
f2.write(", ".join(i))
This is the error I get:
list_of_tasks[i][-1] = str(f"{list_of_tasks[i][-1]}\n")
~~~~~~~~~~~~~^^^
TypeError: list indices must be integers or slices, not list
Ultimately what I'm trying to achieve is to edit parts of each line in this external file. The initial problem I have is the spacing after writing to the file gets messed up hence I'm trying to figure out how to add \n to the last element in the final list in this list of lists.
if it helps here's the full function:
def view_mine(username):
# opens tasks.txt as read only and assigns it as a variable named f1
with open('tasks.txt', 'r') as f1:
x = 1
list_of_tasks= []
other_tasks = []
for line in f1:
line3_split = line.split(', ')
if line3_split[0] == username:
user_format = f"""
Task {x}: {line3_split[1]}
Assigned to: {line3_split[0]}
Date assigned: {line3_split[3]}
Due date: {line3_split[4]}
Task complete? {line3_split[5]}
Task description:
{line3_split[2]}
"""
print(user_format)
x += 1
list_of_tasks.append(line3_split)
else:
other_tasks.append(line3_split)
selection = int(input(f"Which task do you want to select (1-{x-1}) or enter '-1' to return to main menu? ")) -1
if selection == -2:
return
else:
mark_or_edit = int(input(f"To mark as complete enter '1'. To edit the task enter '2'."))
if mark_or_edit == 1:
if list_of_tasks[selection][-1] == "No":
list_of_tasks[selection][-1] = "Yes\n"
elif list_of_tasks[selection][-1] == "No\n":
list_of_tasks[selection][-1] = "Yes\n"
elif mark_or_edit == 2:
user_or_date = int(input("To edit user assigned enter '1'. To edit due date enter '2'. "))
if user_or_date == 1:
user_check = input("Which user do you want to assign this task to? ")
existing_names_list = []
with open('user.txt', 'r') as f:
for line in f:
existing_names = line.split(', ')
existing_names_list.append(existing_names[0])
if user_check in existing_names_list:
list_of_tasks[selection][0] = user_check
else:
print("User does not exist.")
elif user_or_date == 2:
new_date = input("Enter the new due date (XX XXX XXXX): ")
list_of_tasks[selection][4] = new_date
with open('tasks.txt', 'w') as f2:
count = 0
for I in list_of_tasks:
count += 1
if count == len(list_of_tasks):
list_of_tasks[i][-1] = str(f"{list_of_tasks[i][-1]}\n")
f2.write(", ".join(i))
else:
f2.write(", ".join(i))
for i in other_tasks:
f2.write(", ".join(i))
return

The problem is in:
for i in list_of_tasks
In this situation i is a string and you are trying to use it as index in your list.
I am not sure what you are trying to accomplish exactly, but I think your code has some logical inaccuracies. I hope the following code gets the job done:
with open('tasks.txt', 'w') as f2:
count = 0
for sub_list in list_of_tasks:
for i in range(len(sub_list)):
if i == len(sub_list) - 1:
temp = sub_list[i] + '\n'
f2.write(temp)
else:
f2.write(sub_list[i] + ', ')
The output of the above code for the list you provided is:
User, Title of task, Description of task, Date assigned, Due Date, Completed (Yes/No)
with '\n' included in the end, even if it is not obvious.
It seems that you have a list of lists, so a 2D array, in which every element is a string. So you have to loop once for the first dimension (so for each list) and then for the second dimension(so for each string in list). Having every string each time, you are able to create the sentence you are trying to.

Why is my code not posting the requested columns in main def?

I don't expect any coding answers, more just guidance. For my project I have to date-mine apple stock prices from a csv-file and implement it in my code. I provided a sample output below.
https://imgur.com/rPOPN1I
Right now, I am not getting any error messages but my code is not posting the columns requested from the csv.file. Are my definitions at fault or am I missing something else?
# Project No.: 5
# Author: burntchickennuget
# Description: making definitions, reading from a .csv file, validating input, data-mining,
f_list = list()
file_object = ()
my_tot = dict()
new_list = list()
def get_input_descriptor():
while True:
filename = input("Enter a file name: ")
if filename == 'table.csv':
with open(filename, "r") as infile:
infile.readlines()[1:]
# for line in lines:
# print(line.rstrip())
break
else:
print("Bad file name, try again")
return filename
def get_data_list(file_object, column_number):
dict = {}
for val in file_object:
date = val.split(",")[0]
data = float(val.split(",")[column_number])
dict[date] = data
return dict.items()
def average_data(new_list):
for date, price in new_list:
my_tot[date] = my_tot.get(date, 0) + float(price)
my_times[date] = my_times.get(date, 0) + 1
for key in my_tot:
f_list.append((float(my_tot[key] / my_times[key]), key))
def main():
get_input_descriptor()
column_number = int(input("Which column: "))
date_list = get_data_list(file_object, column_number)
final_list = average_data(date_list)
x = sorted(f_list)
print('Lowest 6:')
for tup in x[:6]:
print
tup[0], tup[1]
print('Highest 6:')
x = sorted(f_list, reverse=True)
for tup in x[:6]:
print
tup[0], tup[1]
while 1:
flag = input("do you want to continue? ")
if flag == '' or not flag[0].lower() in ['y', 'n']:
print("Please answer with a yes or no")
else:
break
if flag[0].lower() == 'y':
column = input("Which column: ")
print(column)
if flag[0].lower() == 'n':
print("Bye!")
if __name__ == "__main__":
main()
What can I try next?

Take a look around your get_input_descriptor method.
What are you returning from the method?
Where is the returned information being stored in the main method (is it being stored at all?)
What are you doing with the lines that you read from the file?
What is the file_object you are passing into get_data_list
My main advice would be to add print everywhere for debugging. See what it stored in your variables at different points in the program and see where a variable doesn't contain what you think it should

finding item in text file during 2nd read

In the beginning of my program, i opened a file with f = open("foods.txt", "r+"). Later I called this method i created
def findFood(food):
foodRegex = re.compile(r'(?P<food>\S+)\s+\-.*')
for line in f.readlines():
print line
duplicateFound = re.search(foodRegex, line)
if duplicateFound.group('food') == food:
return duplicateFound
else:
return False
However I run the method again. But my program doesn't work the way I want it to. Specifically
def build_meal_plan():
number_of_items = int(raw_input("How many items would you like to add to your meal plan? "))
count = 0
while number_of_items > 0:
print count
food = raw_input("Enter in food name: ")
print food
if findFood(food):
servings = int(raw_input("Number of servings: "))
else:
print "Food not found! Try again? (y/n): ",
choice = raw_input()
if choice == 'y' or choice == "yes":
number_of_items += 1
else:
return
However during the 2nd run of my findFood method I cannot locate an item i know exists within the .txt file. I am not sure why I cannot find the same item I found in the text file during the first run. My assumption is that you can only go through a txt file once.

Once you call f.readlines(), you are at the end of the file. To return to the start, so you can go through it again, call f.seek(0):
def findFood(food):
foodRegex = re.compile(r'(?P<food>\S+)\s+\-.*')
for line in f.readlines():
...
f.seek(0)
Alternatively, you can import the contents of the file to a list:
def import_file(filename):
with open(filename) as f:
content = [line.strip() for line in f]
return content
And use that instead of referring back to the file.
def findFood(food, data):
foodRegex = re.compile(r'(?P<food>\S+)\s+\-.*')
for line in data:
...
Then you don't need to worry about returning to the start.

Use values saved to a file in order to compute mean/median/mode/etc

I have a program that saves a file that you can write values to. What I am trying to do is use the saved files to calculate my mean/median/mode and to be able to delete values. functions. I am able to add values to the file through the open("filename","a")...but how do I make it so that I am able to import the file values to calculate my other functions?
Sorry its so long, but if anyone can help I would really appreciate it, I am new to figuring out File IO a stuff.
filename = input("What do you want to name your file? Be sure to include .txt after the filename!:")
def main(filename):
print("Now what would you like to do?")
print("--------------------------------------------------------------------------------")
print("Press 1 if you would like to ADD a Value to your list")
print("Press 2 if you would like to DELETE a Value from your list according to its value")
print("Press 3 if you would like to DELETE a Value from your list according to its location")
print("Press 4 if you would like to DISPLAY your List")
print("Press 5 if you would like to COMPUTE MEAN for your list")
print("Press 6 if you would like to COMPUTE MEDIAN for you list")
print("Press 7 if you would like to COMPUTE MIDPOINT for you list")
print("Press 8 if you would like to COMPUTE MODE(S) for your list")
print("Press 9 if you would like to COMPUTE STANDARD DEVIATION for your list")
print("Press 10 if you would like to READ values from a FILE you have made")
print("Press 0 if you would like to EXIT")
print()
execute = int(input("which action would you like to do next?"))
if execute == 1:
add_Values(filename)
if execute == 2:
remove_Value_List(filename)
if execute == 3:
del_Value_Location(filename)
if execute == 4:
read_file(filename)
if execute == 5:
computing_Mean(filename)
if execute == 6:
computing_Median(filename)
if execute == 7:
computing_Midpoint(filename)
if execute == 8:
computing_Modes(filename)
if execute == 9:
computing_Standard_Dev(filename)
if execute == 10:
read_file(filename)
if execute == 0:
print()
print("That's too bad I was having so much fun...but okay...bye!")
if execute >= 12:
print("Sorry but that is not one of the options")
if execute <= -1:
print("Sorry but that is not one of the options")
def add_Values(filename):
fout = open(filename,"a")
again = 'y'
while again == 'y':
fout.write(input("Enter a number you want to write to the file:")+"\n")
print("Do you want to add another number?")
again = input("y = yes, anything else = no:")
fout.close()
print("The numbers have been saved to the file")
main(filename)
def remove_Value_List(filename):
fout = open(filename, "r")
fout.readlines()
remove = "y"
while remove == "y":
print()
print("Here is your list:")
add_Values(filename)
number_list = float(input("Which value should I remove?"))
try:
values.remove(number_list)
print("Here is the revised list:")
print()
print()
except ValueError:
print("That item is not found in the list.")
number_list = float(input("which value should I remove?"))
remove = input("Would you like to remove a value? y = yes, amything else = no:")
fout.close()
print()
main(filename)
def del_Value_Location(filename):
remove = "y"
fout = open(filename,"r")
fout.readlines()
while remove == "y":
print()
print("Here is your list:")
add_Values(filename)
number_list = int(input("Which position should I remove?"))
try:
del values[number_list]
print("Here is the revised list:")
read_file_one(filename)
print()
except ValueError:
print("That item is not found in the list.")
number_list = float(input("which value should I remove?"))
remove = input("Would you like to remove a value? y = yes, amything else = no:")
fout.close()
print()
main(filename)
def computing_Mean(filename):
with open(filename,"r") as fout:
summ = 0
cnt = 0
for line in fout.readlines():
cnt += 1
summ += float(line.strip())
print ("Mean value is:" (summ/cnt))
def computing_Median(filename):
fin = open(filename,"r")
fin.readlines()
ordered = sorted(filename)
length = len(filename)
print("The median of this list is:")
print(float((ordered[length//2] + ordered[-(length+1)//2]))/2)
main(filename)
def computing_Midpoint(filename):
with open(filename,"r") as fout:
filename.sort(key=int)
minNum = min(float(filename))
maxNum = max(float(filename))
print("The midpoint of this list is:")
print((minNum + maxNum) / 2)
main(filename)
def computing_Modes(filename):
from collections import Counter
data = Counter(filename)
print("The Mode(s) of this list is/are:")
print(data.most_common(1))
main(filename)
def computing_Standard_Dev(filename):
mean = sum(filename)/len(filename)
for i in values:
total = 0
newDev = i - mean
squared = newDev**2
total = (total + squared)
divider = (total/(len(values)-1))
standardDev = divider**.5
print("The standard deviation is:")
print(standardDev)
main(filename)
def read_file(filename):
fin = open(filename, 'r')
L = fin.readlines()
for ix in range(len(L)):
L[ix]=L[ix].strip()
while "" in L:
L.remove("")
for ix in range(len(L)):
L[ix]=float(L[ix])
fin.close()
print(L)
main(filename)
main(filename)

There are lots of errors in your code which are very similar to each other so I will explain only one of those similar ones and you should fix others by examining fixed one.
For startes you are opening a file named filename. Using quotes around it makes it a string. You should use it like this:
def add_Values(filename):
fout = open(filename,"w")
But using with statement to open files is much more better because file is closed automatically even if exception is raised.
def add_Values(filename):
with open(filename) as fout:
#do smth
There is no file to work with in def del_Value_Location(filename): and some others. You should open your file in those as well.
To make calculations you need read your data from your file. Which can be achieved by using file.readlines()
def computing_Mean(filename):
with open(filename,"r") as fout:
summ = 0
cnt = 0
for line in fout.readlines():
cnt += 1
summ += int(line.strip())
print ("Mean value is: %.1f" % (summ/cnt))
If you want to change how many digits you want to see, you should change %.1f part.
With this you should fix your other computations by yourself.
About menu, you can do something like this to make it appear again without using a second function.
filename = input("What do you want to name your file? Be sure to include .txt after the filename!:")
#exclude this filename in main and use it as `main`s argument.
def main(filename):
print("Now what would you like to do?")
Ofcoure after this, you should change all main_two()s to main(filename).

Read file error in Python, even though print function is printing the list

I have been trying different ways of writing this code but cannot get past this. Currently the program will run all the way to the write_names(list) function and create the file, and the print function will print the sorted list. The program refuses to get the user input for the search_names() function but it will print anything I ask it to.
Debug highlights: while index < len(list) and in the debug I\O only states "read file error". Hopefully someone has an idea what I'm doing wrong.
'# Abstract: This program creates a list of names. The list is printed,
'# sorted, printed again, written to file, and searched.
'#=============================================================================
'#define the main function
def main():
#try:
##open data file for read
#infile = open('names.txt', 'r')
#call get_names function
list = get_names()
#call print function
print_names(list)
#sort list
list.sort()
#print sorted list
print_names(list)
#write sorted list to new file
write_names(list)
#allow user to search list
search_names(list)
def get_names():
try:
infile = open('names.txt', 'r')
#read file contents into a list
list = infile.readlines()
#close file
infile.close()
#strip \n from each element
index = 0
while index < len(list):
list[index] = list[index].rstrip('\n')
index += 1
return list
except IOError:
print 'Read file error'
def print_names(list):
#print header
print '******************'
#print list line by line
index = 0
while index < len(list):
print list[index]
index += 1
return
def write_names(list):
#open file for writing
outfile = open('sortedNames.txt', 'w')
#write the list to the file
for item in list:
outfile.write(str(item) + '\n')
#close file
outfile.close()
def search_names(list):
#set user test variable
again = 'Y'
while again.upper == 'Y':
#get search from user
search = raw_input('Enter a name to search for: ')
#open list for search
if search in list:
try:
item_index = list.index(search)
print search, 'found.', item_index
except ValueError:
print search, 'not found.'
main()
'
Thanks in advance!

Your issue is that upper is a function, and you are not calling it. Your while in search_names() should read:
while again.upper() == 'Y':

instead of:
#strip \n from each element
index = 0
while index < len(list):
list[index] = list[index].rstrip('\n')
index += 1
return list
just use this list comprehension:
lines = infile.readlines()
infile.close()
return [ line.strip() for line in lines ]
edit:
It looks like you are using an index and a while loop where a for loop can be used.
Instead of:
while index < len(list):
print list[index]
index += 1
use:
# using name_list instead of list
for name in name_list:
print name
also, your search_names() function looks flawed:
def search_names(list):
#set user test variable
again = 'Y'
while again.upper == 'Y':
#get search from user
search = raw_input('Enter a name to search for: ')
#open list for search
if search in list:
try:
item_index = list.index(search)
print search, 'found.', item_index
except ValueError:
print search, 'not found.'
would never exit (again is never reassigned). try:
def search_names(names_list):
again = 'Y'
while again.upper() == 'Y':
s_name = raw_input('Enter a name to search for: ')
if s_name in names_list:
print s_name, 'found.', names_list.index(s_name)
else:
print search, 'not found.'
again = raw_input('Search for another name (Y|N)?: ')
or:
def search_names(names_list):
again = 'Y'
while again == 'Y':
s_name = raw_input('Enter a name to search for: ')
try:
idx = names_list.index(s_name)
print s_name, 'found.', idx
except ValueError:
print search, 'not found.'
again = raw_input('Search for another name (Y|N)?: ').upper()
Which brings up the issue of when to catch exceptions vs using an if statement:
from msdn:
The method you choose depends on how
often you expect the event to occur.
If the event is truly exceptional and
is an error (such as an unexpected
end-of-file), using exception handling
is better because less code is
executed in the normal case. If the
event happens routinely, using the
programmatic method to check for
errors is better. In this case, if an
exception occurs, the exception will
take longer to handle.

Comments begin with #, not '# - you are making every other line of your header a docstring.
You are using an index to iterate across lists, which is inefficient - just iterate on the list items.
Calling a variable list is bad because it prevents you from accessing the list() datatype.
Using with is a more reliable replacement for open() .. close()
again.upper is a function reference - you have to call the function, ie again.upper().
You never change the value of again - this will be an infinite loop!
You test if search in list but then do a try..except block which will only fail if it is not in the list (ie you are testing for the same failure twice).
.
#
# Operate on a list of names
#
def load_names(fname):
try:
with open(fname, 'r') as inf:
return [line.strip() for line in inf]
except IOError:
print "Error reading file '{0}'".format(fname)
return []
def print_names(namelist):
print '******************'
print '\n'.join(namelist)
def write_names(namelist, fname):
with open(fname, 'w') as outf:
outf.write('\n'.join(namelist))
def search_names(namelist):
while True:
lookfor = raw_input('Enter a name to search for (or nothing to quit): ').strip()
if lookfor:
try:
ind = namelist.index(lookfor)
print("{0} found.".format(lookfor))
except ValueError:
print("{0} not found.".format(lookfor))
else:
break
def main():
namelist = load_names('names.txt')
print_names(namelist)
namelist.sort()
print_names(namelist)
write_names(namelist, 'sorted_names.txt')
search_names(namelist)
if __name__=="__main__":
main()