Develop Reference

Python - writing string to HTML file causes computational issues

I appreciate that this may be an issue with my computer/software, but I want to double check that my code isn't causing the problem before ruling it out.
I have written a fairly simple program. I have a short list of strings read in from a text file, then with a different text file open, I iterate over each word in the second text file, checking if the first two letters of the word are contained in the first list of strings.
Then, if that condition is fulfilled, I use string interpolation to insert that word into a string of HTML code. Finally, I append that string to an existing empty .html. When finished iterating through, I close the html file.
with open("strings.txt", "r") as f:
strings = f.read().splitlines()
urlfile = open("links.html", "a")
with open("words.txt", "r") as f:
text = f.read().splitlines()
for word in text:
if word[:2] in strings:
html = '<a href="[URL]/{}">'.format(word)
urlfile.write(html)
urlfile.close()
so far there doesn't actually seem to be any issues with my code doing what I want - I am generating the right html code and if I print it to console it does so quickly. It is being appended to the html file.
The problem I have is that something I am doing must be computationally expensive or problematic, because Notepad++ freezes every time I try to check links.html for the results. I have managed to see that it looks correct, but Notepad++ then becomes unusable, and my computer is clearly straining. The only solution I have is to close anything related to the html file.
None of the lists used are long and all the operations should in theory be quite simple, so I feel as though I must be doing something wrong. Am I writing to files in an unsafe way? Am I doing something wildly expensive that I'm just missing? I am using Notepad++ v7.9.5, Python 3, and Anaconda prompt.
EDIT: I am now able to access the html file on my browser and on Notepad++ without issue. I think the source of the problem was some laptop software updating in the background without me noticing. I'll check that first next time!

How can I make Python using csv read the first word in a line rather than the first character?

I've looked around for solutions to this here, and though they seemed to fit my needs they ended up not working for me. I'm not particularly sure why. I'll try and specify what the issue is and hopefully you'll be able to specify why this was different.
So, I've just been trying to make a simple username and password log-in system using a Tkinter GUI. I've tried making this work by putting the usernames and passwords in an external CSV file, and then having my program, once both users for my game that's already functioning have attempted to log-in, read line-by-line my csv file (called "Accepted Users for Card Game.csv"), which is in the same folder as the program so no further directory is necessary. I've tried making it so that the user puts their username and password into different Tkinter entries, and then presses a button beneath it. The program then checks if, for example, line[0] == PlayerOneUsername and line[1] == PlayerOnePassword, however every time I've tried this, it didn't work. (My delimiter is ',', for anybody wondering).
After making it print what it was reading, I've discovered that it always returns the first character of the line rather than the first word, so of course it keeps on being incorrect. I've searched for an answer, some of which I was already trying, however every time I've tried implementing it, the same issue seems to have been occurring. (EG line.split() hasn't fixed my problem).
This is the output on comparing the line and line[0] next to each other. (Ignore the colours and the title afterwards, those are to do with the game).
Here is the portion of my player two evaluation that triggers when you press the button (it's more or less identical to my player one evaluation):
Success["text"] = ""
if not PasswordLoginInputTwo.get() or not UsernameLoginInputTwo.get():
Success["text"] = "One or more of your password/username entries are empty. Please try again."
else:
csvfile = open ("Accepted Users for Card Game.csv", "r")
Csvreader = csv.reader(csvfile, delimiter = ',')
Success["text"] = "Player Two password/username combination has been read."
for line in csvfile:
print(line[0])
if line:
print(line)
print(line[0])
if line.split(None, 1)[0] == UsernameLoginInputTwo.get() and line.split(None, 1)[1] == PasswordLoginInputTwo.get():
PlayerTwoSuccess = True
PlayerTwoUsername = UsernameLoginInputTwo.get()
PlayerTwoColour = line[2]
PlayerTwoAntithesis = line[3]
PlayerTwoVictorSound = "Victory - "+line[4]+".wav"
PlayerTwoAttempts = PlayerTwoAttempts + 1
The external csv file is just arranged in a simple line format, like this:
PlayerOne,Password1,Purple,Yellow,Donkey Kong
PlayerTwo,Password2,Red,Green,Final Fantasy
PlayerThree,Password3,Pink,Purple,Worms
PlayerFour,Password4,Black,White,Team Fortress 2
I know the answer is probably rather obvious but I'm quite annoyed that I can't seem to find the answer! I'm using Python 2.7 by the way, though I don't intend to carry on using it. (As you can probably tell, I'm extremely new to Python, so please explain any solution like I'm extremely dumb - though you probably already got that impression from my code and the overall problem haha). Thanks!
So basically, to repeat, I am under the impression that line[0] should be the first 'word' in my 'line', in this case being for example "PlayerOne". Instead, it is giving me the first character, in this case, 'P'. How can I rectify this issue? What is causing this? How can I make it so it's the first word rather than the first character? Thank you!

You are iterating over:
for line in csvfile:
Which will return a string representing the first line. You need to loop over the reader object:
for line in Csvreader:
Then, line will be a tuple of the strings split on the delimiter.

Appending a text file to a text file

I've run to a error. I've been trying to append a text file to itself like so:
file_obj = open("text.txt", "a+")
number = 6
def appender(obj, num):
count = 0
while count<=num:
read = file_obj.read()
file_obj.seek(0,2)
file_obj.write(read)
count+=1
appender(file_obj, number)
However, the text.txt file is then filled with strange ASCII symbols. At first, the file contains only a simple "hello", but after the code, it contains this:
hellohello䀀 猀· d娀 Ť搀Ŭ娀ͤ攀ɪ昀Ѥ萀 夀ɚ搀ť樀Ŧ搀茀 婙ݤ攀Ѫ昀ࡤ萀 夀њ搀
ɥ攀ժ昀൤
茀 婙୤攀ť樀ɦ搀茀 婙൤萀 ݚ搀࡚攀४攀ƃ娀਍搀⡓ 癳  祐桴湯䌠慨慲瑣牥䴠灡楰杮
䌠摯捥挠ㅰ㔲‰敧敮慲整⁤牦浯✠䅍偐义升嘯久佄卒䴯䍉䙓⽔䥗䑎坏⽓偃㈱〵吮员‧楷桴朠湥潣敤⹣祰
മഊ椊 and so on.
Any help will be appreciated

I think I can fix your problem, even though I can't reproduce it. There's a logic error: after you write, you fail to return to the start of the file for reading. In terms of analysis, you failed to do anything to diagnose the problem. At the very least, use a print statement to see what you're reading: that highlights the problem quite well. Here's the loop I used:
count = 0
while count<=num:
file_obj.seek(0) # Read from the beginning of the file.
read = file_obj.read()
print(count, read) # Trace what we're reading.
file_obj.seek(0, 2)
file_obj.write(read)
count+=1
This gives the expected output of 128 (2^(6+1)) repetitions of "hello".
EXTENSIONS
I recommend that you learn to use both the for loop and the with open ... as idiom. These will greatly shorten your program and improve the readability.

I am using this code and everything is working as expected:
with open("file.txt") as f:
for line in f:
f.write(line)

You just have the wrong mode - use 'r+' rather than 'a+'. See this link for a list of modes and an explanation of reading files.

Python conditional statement based on text file string

Noob question here. I'm scheduling a cron job for a Python script for every 2 hours, but I want the script to stop running after 48 hours, which is not a feature of cron. To work around this, I'm recording the number of executions at the end of the script in a text file using a tally mark x and opening the text file at the beginning of the script to only run if the count is less than n.
However, my script seems to always run regardless of the conditions. Here's an example of what I've tried:
with open("curl-output.txt", "a+") as myfile:
data = myfile.read()
finalrun = "xxxxx"
if data != finalrun:
[CURL CODE]
with open("curl-output.txt", "a") as text_file:
text_file.write("x")
text_file.close()
I think I'm missing something simple here. Please advise if there is a better way of achieving this. Thanks in advance.

The problem with your original code is that you're opening the file in a+ mode, which seems to set the seek position to the end of the file (try print(data) right after you read the file). If you use r instead, it works. (I'm not sure that's how it's supposed to be. This answer states it should write at the end, but read from the beginning. The documentation isn't terribly clear).
Some suggestions: Instead of comparing against the "xxxxx" string, you could just check the length of the data (if len(data) < 5). Or alternatively, as was suggested, use pickle to store a number, which might look like this:
import pickle
try:
with open("curl-output.txt", "rb") as myfile:
num = pickle.load(myfile)
except FileNotFoundError:
num = 0
if num < 5:
do_curl_stuff()
num += 1
with open("curl-output.txt", "wb") as myfile:
pickle.dump(num, myfile)
Two more things concerning your original code: You're making the first with block bigger than it needs to be. Once you've read the string into data, you don't need the file object anymore, so you can remove one level of indentation from everything except data = myfile.read().
Also, you don't need to close text_file manually. with will do that for you (that's the point).

Sounds more for a job scheduling with at command?
See http://www.ibm.com/developerworks/library/l-job-scheduling/ for different job scheduling mechanisms.

The first bug that is immediately obvious to me is that you are appending to the file even if data == finalrun. So when data == finalrun, you don't run curl but you do append another 'x' to the file. On the next run, data will be not equal to finalrun again so it will continue to execute the curl code.
The solution is of course to nest the code that appends to the file under the if statement.

Well there probably is an end of line jump \n character which makes that your file will contain something like xx\n and not simply xx. Probably this is why your condition does not work :)
EDIT
What happens if through the python command line you type
open('filename.txt', 'r').read() # where filename is the name of your file
you will be able to see whether there is an \n or not

Try using this condition along with if clause instead.
if data.count('x')==24
data string may contain extraneous data line new line characters. Check repr(data) to see if it actually a 24 x's.

Write strings to another file

The Problem - Update:
I could get the script to print out but had a hard time trying to figure out a way to put the stdout into a file instead of on a screen. the below script worked on printing results to the screen. I posted the solution right after this code, scroll to the [ solution ] at the bottom.
First post:
I'm using Python 2.7.3. I am trying to extract the last words of a text file after the colon (:) and write them into another txt file. So far I am able to print the results on the screen and it works perfectly, but when I try to write the results to a new file it gives me str has no attribute write/writeline. Here it the code snippet:
# the txt file I'm trying to extract last words from and write strings into a file
#Hello:there:buddy
#How:areyou:doing
#I:amFine:thanks
#thats:good:I:guess
x = raw_input("Enter the full path + file name + file extension you wish to use: ")
def ripple(x):
with open(x) as file:
for line in file:
for word in line.split():
if ':' in word:
try:
print word.split(':')[-1]
except (IndexError):
pass
ripple(x)
The code above works perfectly when printing to the screen. However I have spent hours reading Python's documentation and can't seem to find a way to have the results written to a file. I know how to open a file and write to it with writeline, readline, etc, but it doesn't seem to work with strings.
Any suggestions on how to achieve this?
PS: I didn't add the code that caused the write error, because I figured this would be easier to look at.
End of First Post
The Solution - Update:
Managed to get python to extract and save it into another file with the code below.
The Code:
inputFile = open ('c:/folder/Thefile.txt', 'r')
outputFile = open ('c:/folder/ExtractedFile.txt', 'w')
tempStore = outputFile
for line in inputFile:
for word in line.split():
if ':' in word:
splitting = word.split(':')[-1]
tempStore.writelines(splitting +'\n')
print splitting
inputFile.close()
outputFile.close()
Update:
checkout droogans code over mine, it was more efficient.

Try this:
with open('workfile', 'w') as f:
f.write(word.split(':')[-1] + '\n')
If you really want to use the print method, you can:
from __future__ import print_function
print("hi there", file=f)
according to Correct way to write line to file in Python. You should add the __future__ import if you are using python 2, if you are using python 3 it's already there.

I think your question is good, and when you're done, you should head over to code review and get your code looked at for other things I've noticed:
# the txt file I'm trying to extract last words from and write strings into a file
#Hello:there:buddy
#How:areyou:doing
#I:amFine:thanks
#thats:good:I:guess
First off, thanks for putting example file contents at the top of your question.
x = raw_input("Enter the full path + file name + file extension you wish to use: ")
I don't think this part is neccessary. You can just create a better parameter for ripple than x. I think file_loc is a pretty standard one.
def ripple(x):
with open(x) as file:
With open, you are able to mark the operation happening to the file. I also like to name my file object according to its job. In other words, with open(file_loc, 'r') as r: reminds me that r.foo is going to be my file that is being read from.
for line in file:
for word in line.split():
if ':' in word:
First off, your for word in line.split() statement does nothing but put the "Hello:there:buddy" string into a list: ["Hello:there:buddy"]. A better idea would be to pass split an argument, which does more or less what you're trying to do here. For example, "Hello:there:buddy".split(":") would output ['Hello', 'there', 'buddy'], making your search for colons an accomplished task.
try:
print word.split(':')[-1]
except (IndexError):
pass
Another advantage is that you won't need to check for an IndexError, since you'll have, at least, an empty string, which when split, comes back as an empty string. In other words, it'll write nothing for that line.
ripple(x)
For ripple(x), you would instead call ripple('/home/user/sometext.txt').
So, try looking over this, and explore code review. There's a guy named Winston who does really awesome work with Python and self-described newbies. I always pick up new tricks from that guy.
Here is my take on it, re-written out:
import os #for renaming the output file
def ripple(file_loc='/typical/location/while/developing.txt'):
outfile = "output.".join(os.path.basename(file_loc).split('.'))
with open(outfile, 'w') as w:
lines = open(file_loc, 'r').readlines() #everything is one giant list
w.write('\n'.join([line.split(':')[-1] for line in lines]))
ripple()
Try breaking this down, line by line, and changing things around. It's pretty condensed, but once you pick up comprehensions and using lists, it'll be more natural to read code this way.

You are trying to call .write() on a string object.
You either got your arguments mixed up (you'll need to call fileobject.write(yourdata), not yourdata.write(fileobject)) or you accidentally re-used the same variable for both your open destination file object and storing a string.