Python 3.5.1 reading from a file - python-3.5

I have written a maths quiz for school and the final task requires me to take scores from a file and order them in various ways. I was performing what I thought was a simple task of just writing to a file but it turned out to not work. Can someone please tell me what's missing from this.
with open("Class A.txt", "r") as f:
list(f)

How about this:
>>> with open("Class A.txt", "r") as f:
... content = f.read()
... content_list = content.split('\n') # split on space/comma/...
Read the content and then split it using whichever delimiter you have used, whether enter (\n), comma or anything else.

if the file is already in the format of a list i.e. [1,2,3,4,5], all you have to do is use the eval function. you could try one of the following:
with open("Class A.txt", "r") as f: #method 1, requires indentation
f1 = eval(f.read())
print(f1)
file = open("Class A.txt", "r") #method 2
f2 = eval(file.read())
file.close()
print(f2)
if your string is like this "6|Louis|Perry 2|Shiro|Ski 4|A|B", you could do
file = open("Class A.txt", "r")
f2 = file.read().split('|')
file.close()
print(f2)

Related

How can I merge two files with numbers into a new file and make it sorted?

How can I merge two files with numbers into a new file and make it sorted?
Code:
#combining the two files
filenames = ["numbers1.txt", "numbers2.txt"]
with open("allNumbers.txt", "w") as al_no:
**#iterating through the filenames list**
for f in filenames:
with open(f) as infile:
for line in infile:
al_no.write(line)
There are two approaches you can use.
The first approach is to loop through, append the lines to a list, sort the list and then write that out to the file.
filenames = ["numbers1.txt", "numbers2.txt"]
# Step 1: merge the lines into a list
lines = []
for f in filenames:
with open(f) as infile:
for line in infile:
lines.append(line)
# Step 2: write the list out to the file in a sorted order
with open("allNumbers.txt", "w") as all_no:
all_no.write(''.join(sorted(lines, key=lambda x: int(x.strip()))))
It is more succinct (and Pythonic) to use list comprehensions instead:
filenames = ["numbers1.txt", "numbers2.txt"]
lines = [line for sublist in [open(f).readlines() for f in filenames] for line in sublist]
with open("allNumbers.txt", "w") as all_no:
all_no.write(''.join(sorted(lines, key=lambda x: int(x.strip()))))
Remember that when sorting, you need to use the key argument to sorted to ensure a numeric sort is done, rather than the default lexicographic sort.
This code assumes that each line in the source files contains a number, which is likely given the current approach you've taken.
You did not provide a detailed description or file, I worked on it with a prediction.
try this code:
# Reading data from file1
with open('numbers1.txt') as fp:
data = fp.read()
# Reading data from file2
with open('numbers2.txt') as fp:
data2 = fp.read()
# Merging 2 files
data += "\n"
data += data2
# Covert str to list
list_data = data.split()
# Covert list(item) to int
list_data = list(map(int, list_data))
# Sort list(item)
list_data.sort()
# save file
with open('allNumbers.txt', 'w') as file:
for data in list_data:
file.write("%s\n" % data)
You can change the structure and use it.
good luck!

read and write from and to file using functions

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!

Unable to save the file correctly

I have a text file contains a text about a story and I want to find a word "like" and get the next word after it and call a function to find synonyms for that word. here is my code:
file = 'File1.txt'
with open(file, 'r') as open_file:
read_file = open_file.readlines()
output_lines = []
for line in read_file:
words = line.split()
for u, word in enumerate(words):
if 'like' == word:
next_word = words[u + 1]
find_synonymous(next_word )
output_lines.append(' '.join(words))
with open(file, 'w') as open_file:
open_file.write(' '.join(words))
my only problem I think in the text itself, because when I write one sentence including the word (like) it works( for example 'I like movies'). but when I have a file contains a lot of sentences and run the code it deletes all text. can anyone know where could be the problem
You have a couple of problems. find_synonymous(next_word ) doesn't replace the word in the list, so at best you will get the original text back. You do open(file, 'w') inside the for loop, so the file is overwritten for each line. next_word = words[u + 1] will raise an index error if like happens to be the last word on the line and you don't handle the case where the thing that is liked continues on the next line.
In this example, I track an "is_liked" state. If a word is in the like state, it is converted. That way you can handle sentences that are split across lines and don't have to worry about index errors. The list is written to the file outside the loop.
file = 'File1.txt'
with open(file, 'r') as open_file:
read_file = open_file.readlines()
output_lines = []
is_liked = False
for line in read_file:
words = line.split()
for u, word in enumerate(words):
if is_liked:
words[u] = find_synonymous(word)
is_liked = False
else:
is_liked = 'like' == word
output_lines.append(' '.join(words) + '\n')
with open(file, 'w') as open_file:
open_file.writelines(output_lines)

append content of text file to other python

I'm a "basic" python user and I'm trying to do following:
There is a file "input.txt" which is created each 5 minutes with different content. Now I'm just trying,each time the file is generated, to copy (or better to say to append) the whole content to an file "output.txt":
with open("input.txt",'r') as f:
lines = f.readlines()
with open("output.txt", "a") as f1:
f1.writelines("lines\n")
f1.write("--This-is-just-a-line-to-differ-the-content-blocks")
Now, I'm able to copy the content, but the file "output.txt" is each time overwritten. What I'm doing wrong?
That happened because you are writing the output file, not the input file
with open("file.txt",'r') as f:
lines = f.readlines()
with open("output.txt", "w") as f1:
f1.writelines(lines)
f1.write("--This-is-just-a-line-to-differ-the-content-blocks")
f.close()
f1.close()
So it worked with:
with open("file.txt",'r') as f:
lines = f.readlines()
with open("output.txt", "a") as f1:
f1.writelines(lines)
f1.write("--This-is-just-a-line-to-differ-the-content-blocks")
f.close()
f1.close()
#Reinier Hernández Ávila: Thx for the tipp with f.close(). But in this case the overwriting argument "a" worked and not the "w".

Python-2.7 write to file

I have this script:
f = open("/ggg/darr/file/", "r+")
a = 0
for line in f:
if a ==58:
print (line)
line1 = "google.ca"
f.write(line1)
print line
a = a+1
f.close()
I want to keep my file but only to change what is written on line 58 to "google.ca"
then save it
using linux: mint-17.2
# Read data from file
with open('yourfile.txt', 'r') as file:
# read all line in the file to data array
data = file.readlines()
# change data on line 58 (array start from 0)
data[57] = 'Data you need to change'
# Write data back
with open('yourfile.txt', 'w') as file:
file.writelines(data)
You need to decide whether you want to write a new file (with print) or change the old file (with r+ mode and f.write). You will probably be happiest if you write a new file.
dataRead = []
f = open("/ggg/darr/file/", "r+")
a = 0
for line in f:
if a == 58:
line = "google.ca"
dataRead.append(line)
a = a+1
f.close()
f2 = open("/some/new/file","w")
for line in dataRead:
f2.write(line)
f2.close()
With the answer of Adisak Anusornsrirung I wrote it like this:
with open('sss.txt','r') as file:
data = file.readlines()
print (data[14])
file.close()
data[14] = "some data here"+"\n"
with open ("sss.txt", 'w') as file:
file.writelines(data)
file.close()
f = open("sss.txt", 'r')
print (f.read())
f.close()

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