I grabbed an array from the lines of a txt file. The problem is I only need the end of these lines. I'm still pretty new to Python so I'm not sure how to put these concepts together. Below is my best attempt, the first part works but the second falls apart.
with open("prices.txt") as f:
readline = f.readlines()
for seatCapacity in readline:
seatCapacity = readline[10:]
I guess, you want like this.
with open("prices.txt") as f:
for line in f:
seatCapacity = line[10:]
you can refer this solution: How should I read a file line-by-line in Python?
Related
I have started to make an anagram solver with Python, but since I was using a lot of words (every word in the English dictionary), I didn't want them as an array in my Python file and instead had them in a separate text file called dictionaryArray2.txt.
I can easily import my text file and display my words on the screen using Python but I cannot find a way to select a specific element from the array rather than displaying them all.
When I do print(dictionary[2]) it prints the second letter of the whole file rather than the second element of the array. I never get any errors. it just doesn't work.
I have tried multiple things but they all have the same output.
My code below:
f = open("dictionaryArray2.txt", "r")
dictionary = f.read()
f.close()
print(dictionary[2])
If you want to split the content of dictionaryArray2 into separate words, do:
f = open("dictionaryArray2.txt", "r")
dictionary = f.read()
f.close()
print(dictionary[2])
If you want to split the content of dictionaryArray2 into separate lines, do:
f = open("dictionaryArray2.txt", "r")
dictionary = f.readlines()
f.close()
words = dictionary.split()
print(words[2])
I think the problem is, you're reading the entire file into a single long list. If your input dictionary is one word per line, I think what you want is to get a text file like this:
apple
bat
To something like this:
dictionary = ['apple', 'bat']
There's an existing answer that might offer some useful code examples, but in brief, f.read() will read the entire file object f. f.readlines(), on the other hand, iterates over each line one at a time.
To quote from the official Python docs:
If you want to read all the lines of a file in a list you can also use list(f) or f.readlines().
hope this is not a trivial question since I'm new to Python.
I have a text file, and I need to compare the first line with all the following ones, than the second line with all the following ones, etc.
If it was a list I'd just make two for loops, but I don't know how to start reading a file from the line after the one that needs to be compared.
Could someone help me?
You can get a list with each line as an element using a readlines() function.
with open(file_name) as file:
lines_list = f.readlines()
This will give you a list of all the lines:
with open(path_to_file) as f:
list_of_lines = f.readlines()
for line in f1:
for line_aux in f2:
compare the two lines
I'm trying to write a simple Phyton script that alway delete the line number 5 in a tex file, and replace with another string always at line 5. I look around but I could't fine a solution, can anyone tell me the correct way to do that? Here what I have so far:
#!/usr/bin/env python3
import od
import sys
import fileimput
f= open('prova.js', 'r')
filedata = f,read()
f.close ()
newdata = "mynewstring"
f = open('prova.js', 'w')
f.write(newdata, 5)
f.close
basically I need to add newdata at line 5.
One possible simple solution to remove/replace 5th line of file. This solution should be fine as long as the file is not too large:
fn = 'prova.js'
newdata = "mynewstring"
with open(fn, 'r') as f:
lines = f.read().split('\n')
#to delete line use "del lines[4]"
#to replace line:
lines[4] = newdata
with open(fn,'w') as f:
f.write('\n'.join(lines))
I will try to point you in the right direction without giving you the answer directly. As you said in your comment you know how to open a file. So after you open a file you might want to split the data by the newlines (hint: .split("\n")). Now you have a list of each line from the file. Now you can use list methods to change the 5th item in the list (hint: change the item at list[4]). Then you can convert the list into a string and put the newlines back (hint: "\n".join(list)). Then write that string to the file which you know how to do. Now, see if you can write the code yourself. Have fun!
I am trying to write a python script to read in a large text file from some modeling results, grab the useful data and save it as a new array. The text file is output in a way that has a ## starting each line that is not useful. I need a way to search through and grab all the lines that do not include the ##. I am used to using grep -v in this situation and piping to a file. I want to do it in python!
Thanks a lot.
-Tyler
I would use something like this:
fh = open(r"C:\Path\To\File.txt", "r")
raw_text = fh.readlines()
clean_text = []
for line in raw_text:
if not line.startswith("##"):
clean_text.append(line)
Or you could also clean the newline and carriage return non-printing characters at the same time with a small modification:
for line in raw_text:
if not line.startswith("##"):
clean_text.append(line.rstrip("\r\n"))
You would be left with a list object that contains one line of required text per element. You could split this into individual words using string.split() which would give you a nested list per original list element which you could easily index (assuming your text has whitespaces of course).
clean_text[4][7]
would return the 5th line, 8th word.
Hope this helps.
[Edit: corrected indentation in loop]
My suggestion would be to do the following:
listoflines = [ ]
with open(.txt, "r") as f: # .txt = file, "r" = read
for line in f:
if line[:2] != "##": #Read until the second character
listoflines.append(line)
print listoflines
If you're feeling brave, you can also do the following, CREDITS GO TO ALEX THORNTON:
listoflines = [l for l in f if not l.startswith('##')]
The other answer is great as well, especially teaching the .startswith function, but I think this is the more pythonic way and also has the advantage of automatically closing the file as soon as you're done with it.
How would I pull text from a specific text line, inside a text file using Python?
If you want to read the 10th line:
with open("file.txt") as f:
for i in range(9):
f.next()
print f.readline()
This doesn't read the whole file in memory.
The simplest method:
print list( open('filename') )[line_number]
That's gonna read in the whole file which may not be a good idea. A more efficient technique would depend on how you are using it.
The following Python example should extract the correct line number, but it is horribly inefficient:
f = open('file.txt')
print f.readlines()[line_number]