For the first part of the program i opened a file which is prompted by the user, then wrote code to read, in turn, each line of the file, remove the newline character and append the resulting string to a list of strings.
After the input is complete the grid should be displayed on the screen. But my code is not working according to the instructions, need help please. Below is the code i have done so far:
x = {}
file = input("Enter a filename: ")
try:
a = open(file)
with open(file) as a:
x = [line.strip() for line in a]
a.close()
except IOError as e:
print ("File Does Not Exist")
Not sure what isn't working. You have some unnecessary code. Here is a version that works fine for me:
# x = {}
file = input('enter a filename')
try:
# a = open(file)
with open(file) as a:
x = [line.strip() for line in a]
a.close()
except IOError as e:
print ("File Does Not Exist")
print(x)
Note that i have commented out the unnecessary lines and added a print statement so that you can see the contents of x
Related
I'm trying to create 2 functions.
readfiles(file_path), That reads a file specified by file_path and returns a list of strings containing each line in the file.
writefiles(lines, file_path) That writes line by line the content of the list lines to the file specified by file_path.
When used one after another the output file should be an exact copy of the input file(including the formatting)
This is what i have so far.
file_path = ("/myfolder/text.txt", "r")
def readfiles(file_path):
with open file_path as f:
for line in f:
return line
lst = list[]
lst = line
lst.append(line)
return lst
read_file(file_path)
lines = lst []
def writefiles(lines, file_path):
with open ("file_path", "w") as f:
for line in lst:
f.write(line)
f.write("\n")
I can get it to kind of work when I use this for read
with open("/myfolder/text.txt", "r") as f:
for line in f:
print(line, end='')
and this for write
with open ("/myfolder/text.txt", "w") as f:
for line in f:
f.write(line)
f.write("\n")
But when I try to put them into functions it all messes up.
I'm not sure why, I know it's a simple question but it's just not clicking for me. I've read documentation on it but I'm not following it fully and am at my wits end. What's wrong with my functions?
I get varying errors from
lst = list[]
^
SyntaxError: invalid syntax
to
lst or list is not callable
Also I know there are similar questions but the ones I found don't seem to define a function.
The problems with your code are explained as comments
file_path = ("/myfolder/text.txt", "r") # this is a tupple of 2 elements should be file_path = "/myfolder/text.txt"
def readfiles(file_path):
with open file_path as f: # "open" is a function and will probably throw an error if you use it without parenthesis
# use open this way: open(file_path, "r")
for line in f:
return line # it will return the first line and exit the function
lst = list[] # "lst = []" is how you define a list in python. also you want to define it outside the loop
lst = line # you are replacing the list lst with the string in line
lst.append(line) # will throw an error because lst is a string now and doesn't have the append method
return lst
read_file(file_path) # should be lines = read_file(file_path)
lines = lst [] # lines is an empty list
def writefiles(lines, file_path):
with open ("file_path", "w") as f:
for line in lst: # this line should have 1 more tabulation
f.write(line) # this line should have 1 more tabulation
f.write("\n") # this line should have 1 more tabulation
Here's how the code should look like
def readfiles(file_path):
lst = []
with open(file_path) as f:
for line in f:
lst.append(line.strip("\n"))
return lst
def writefiles(lines, file_path):
with open(file_path, "w") as f:
for line in lines:
f.write(line + "\n")
file_path = "/myfolder/text.txt"
filepathout = "myfolder/text2.txt"
lines = readfiles(file_path)
writefiles(lines, filepathout)
A more pythonic way to do it
# readlines is a built-in function in python
with open(file_path) as f:
lines = f.readlines()
# stripping line returns
lines = [line.strip("\n") for line in lines]
# join will convert the list to a string by adding a \n between the list elements
with open(filepathout, "w") as f:
f.write("\n".join(lines))
key points:
- the function stops after reaching the return statement
- be careful where you define your variable.
i.e "lst" in a for loop will get redefined after each iteration
defining variables:
- for a list: list_var = []
- for a tuple: tup_var = (1, 2)
- for an int: int_var = 3
- for a dictionary: dict_var = {}
- for a string: string_var = "test"
A couple learning points here that will help.
In your reading function, you are kinda close. However, you cannot put the return statement in the loop. As soon as the function hits that anywhere for the first time, it ends. Also, if you are going to make a container to hold the list of things read, you need to make that before you start your loop. Lastly, don't name anything list. It is a keyword. If you want to make a new list item, just do something like: results = list() or results = []
So in pseudocode, you should:
Make a list to hold results
Open the file as you are now
Make a loop to loop through lines
append to the results list
return the results (outside the loop)
Your writefiles is very close. You should be looping through the lines variable that is a parameter of your function. Right now you are referencing lst which is not a parameter of your function.
Good luck!
while True:
try:
line = input("paste:")
except EOFError:
break
f = open("notam_new.txt", "w+")
f.write(line)
f.close()
This code return only the last line of multi-line after Ctrl+D
I tried also:
notam = input("paste new notam: ")
f = open("notam_new.txt", "w+")
f.write(notam)
f.close()
getting only the first row.
Any ideas?
You're setting line in a loop, so every iteration you're just overwriting said line with the next one You need to accumulate your lines in a list (created before the while True) so you can keep track of all of them, and then write to the file in a loop. Plus you also need to add a newline as input() strips it.
lines = []
while True:
try:
lines.append(input("paste:"))
except EOFError:
break
with open("notam_new.txt", "w+") as f:
for line in lines:
f.write(line)
f.write('\n')
This is what I'vre tried so far:
print('''You will have to enter a file name
Once the file name has been entered, the program will then print out your ASCII art''')
file_name = input('Enter file name: ')
with open(file_name) as file_handle:
for line in file_handle:
for x in f:
print(x)
one for loop should be removed from your code as commented and you should print line.
print('''You will have to enter a file name
Once the file name has been entered, the program will then print out your ASCII art''')
file_name = input('Enter file name: ')
with open(file_name) as file_handle:
for line in file_handle:
#for x in f:
print(line)
def gameinfo():
lines = []
html_doc = 'STATIC.html'
soup = BeautifulSoup(open(html_doc), 'html.parser')
for mytable in soup.find_all('table'):
for trs in mytable.find_all('tr'):
tds = trs.find_all('td')
row1 = [elem.text.strip() for elem in tds]
row = str(row1)
sausage = False
with open("FIRE.txt", "r+") as file:
for line in file:
if row+"\n" in line:
break
else:
if row.split(",")[:4] == line.split(",")[:4]:
print(row)
print(line)
file.write(line.replace(line+"\n", row+"\n"))
print('Already exists with diff date')
sausage = True
break
if sausage == False:
print(row.split(",")[:4])
print(line.split(",")[:4])
print(row)
print(line)
file.write(row+"\n")
print('appended')
while True:
gameinfo()
gameinfo()
This program is supposed to keep searching the text file FIRE.txt for lines that match the variable row. When i run it, it works okay, but the part of the code that is supposed to check if the first four elements of the list are the same, and then skin the appending section below, doesn't work. When the program detects that the first 4 elements of a string turned into a list(row) that matches with another string's first 4 elements that's in the text file, it should overwrite the string in the text file. However when it detects a list that has the same first 4 elements, it loops forever and never breaks out.
My string looks like this:
['Infield Upper Deck Reserved 529', '$17.29', '4', '2', '175']
and i compare it to a list that looks like this:
['Infield Upper Deck Reserved 529', '$17.29', '4', '2', '170']
and when it sees that the first 4 elements in the list are the same, it should overwrite the one that was in the text file to begin with, but it is looping.
Question has changed; most recent version last.
Methinks you want to use the csv module. If you iterate through a csv.reader object instead of the file object directly, you'll get each line as a a list.
Example:
import csv
row = ["this", "is", "an", "example"]
with open("FIRE.txt", "r+") as file:
reader = csv.reader(file)
for line in reader:
if row in line:
break
pass
Alternatively, if you don't need to use this in anything other than Python, you could pickle a collections.OrderedDict with a tuple of the first four items as the keys:
import collections
import pickle
import contextlib
#contextlib.contextmanager
def mutable_pickle(path, default=object):
try:
with open(path, "rb") as f:
obj = pickle.load(f)
except IOError, EOFError:
obj = default()
try:
yield obj
finally:
with open(path, "wb") as f:
pickle.dump(obj, f)
with mutable_pickle("fire.bin",
default=collections.OrderedDict) as d:
for row in rows:
d[tuple(row[:4])] = row
I am fairly new to python.
I am trying to make a script that will read sudoku solutions and determent if they are correct or not.
Things I need:
1] Prompt the user to enter a file/file path which includes the sudoku numbers. Its a .txt file of 9 rows and columns. Consist only of numbers.
2] Have some kind of an error handling.
3] Then, if the sudoku is valid, i should create a new text file using the same format as the original input file with the prefix "Correct_"
I have not fully finished the program, but I get this error when I put a false path or file name.
Hello to Sudoku valitator,
Please type in the path to your file and press 'Enter': example.txt #This is a non existing file, to test the Error Exception
'Traceback (most recent call last):
File "C:/Users/FEDROS/Desktop/bs.py", line 9, in <module>
sudoku = open(prompt, 'r').readlines()
FileNotFoundError: [Errno 2] No such file or directory: 'example.txt'
Here is my script:
while True:
try:
prompt = input("\n Hello to Sudoku valitator,"
"\n \n Please type in the path to your file and press 'Enter': ")
break
except (FileNotFoundError, IOError):
print("Wrong file or file path")
sudoku = open(prompt, 'r').readlines()
def check(game):
n = len(game)
if n < (1):
return False
for i in range(0, n):
horizontal = []
vertical = []
for k in range(0, n):
if game[k][i] in vertical:
return ("File checked for errors. Your options are wrong!")
vertical.append(game[k][i])
if game[i][k] in horizontal:
return ("File checked for errors. Your options are wrong!")
horizontal.append(game[i][k])
return ("File checked for errors. Your options are correct!")
print (check(sudoku))
Thanks, any advice or help will be appreciated.
try block should be around open. Not around prompt.
while True:
prompt = input("\n Hello to Sudoku valitator,"
"\n \n Please type in the path to your file and press 'Enter': ")
try:
sudoku = open(prompt, 'r').readlines()
except FileNotFoundError:
print("Wrong file or file path")
else:
break
You can try adding this code before open() function:
import os
pathname = __file__
os.chdir(os.path.dirname(pathname))