I don't understand how readlines() works in Python, in this case Python 2. Let me explain, I have the following function in a file that I use in other files via "import", like a package.
def openFileForReading(filePath):
if not fileExists(filePath):
print 'The file, ' + filePath + 'does not exist - cannot read it.'
return ''
else:
fileHandle = open(filePath, 'r')
return fileHandle
In my new program, I do this:
openFileRead = openFileForReading("Orden.txt")
lineList = openFileRead.readlines()
print lineList
And the output it gives me is:
[]
But if I do this, directly in the file, without using my package function, it works:
fileHandle = open("Orden.txt", 'r')
lineList = fileHandle.readlines()
print lineList
Why if I do this directly it works but if I do by a function of a package, don't?
P.S.: The "Orden.txt" file is not empty, it has two lines:
Orden.txt
Line number 1
Line number 2
Related
I am trying to use three files in which the first is the text file that contains the names of 3 different zip files. I then want to open those 3 files and write their contents into a separate text file. I have the pseudocode for this program but I am unable to figure out what to do. I have some code but I don't know if it is correct for this program. I am not very advanced in python yet so I would like to run this code using concept that are mostly in my code or easier code that can help me get a walk through of how to make and run this program.
Pseudocode:
Input File – List of zip file names with location
Read each line from the input file, read the contents of the zip file and write it to the output file
Output File – print the list of the files/contents inside the zip file
Here is the code I have so far:
import zipfile
write_file = open('file.txt' , "w")
input_file = open('C:\\Users\\Tanish L\\OneDrive\\InputReadFile.txt','r')
i = 0
readfile = input_file.readlines()
a = True
for line in readfile:
while a == True:
print(readfile[0:i])
i = int(i) + 1
if i > len(readfile):
a = False
file_names = zipfile.ZipFile(#file line from input_file,'r')
for name in file_names.namelist():
write_file.write('%s' % (name) + "\n")
file_names.close()
write_file.close()
import zipfile
write_file = open('file.txt' , "w")
input_file = open('C:\\Users\\Tanish L\\OneDrive\\InputReadFile.txt','r')
i = 0
readfile = input_file.readlines()
for line in readfile:
f = zipfile.ZipFile(line.rstrip())
for name in f.namelist():
write_file.write(name + "\n")
f.close()
write_file.close()
Explanation:
You already loop over the lines in readfile (array) with the for loop and don't need a counter controlled while loop as well.
You then open the zipfile with the filename of that line (rstrip removes the newline '\n' at the end).
Then loop over the files in the zip file using namelist, and write that to your write file.
The text file is "ics2o.txt" and I don't know how to print numbers next to the lines
import random
print ("----------------------------------------------------------")
print ("Student Name Student Mark")
print ("----------------------------------------------------------")
f = open("ics2o.txt")
for line in f:
x = len(f.readlines())
for i in range (x):
contents = f.read()
print(str(contents) + str(random.randint(75,100)))
for line in f:
x = len(f.readlines())
for i in range (x):
contents = f.read()
print(str(contents) + str(random.randint(75,100)))
The problem is that you are reading the file in at least 3 different ways which causes none of them to work the way you want. In particular, f.readlines() consumes the entire file buffer, so when you next do f.read() there is nothing left to read. Don't mix and match these. Instead, you should use line since you are iterating over the file already:
for line in f:
print(line + str(random.randint(75,100)))
The lesson here is don't make things any more complicated than they need to be.
Firstly, doing print("----...") is a bad practice, at least use string multiplication:print("-"*10)
Secondly, always open files using 'with' keyword. (u can google it up why)
Thirdly, the code:
with open("ics2o.txt") as f:
for i,j in enumerate(f):
print(i,j)
Noob here. I need to read in a file, using the read (rather than readlines()) method (which provides the input to several functions), and identify all of the lines in that file (i.e. to print or to append to a list).
I've tried join, split, appending to lists, all with little to show.
# Code I'm stuck with:
with open("text.txt", 'r') as file:
a = file.read()
# Stuff that doesn't work
for line in a:
# can't manipulate when using the below, but prints fine
# print(line, end = '')
temp = (line, end = '')
for line in a:
temp = ''
while not ' ':
temp += line
new = []
for i in a:
i = i.strip()
I tend to get either everything in a long string, or
'I', ' ', 't','e','n','d',' ', 't','o' .... get individual chars. I'm just looking to get each line up to the newline char \n, or basically, what readlines() would give me, despite the file being stored in memory using read()
with open('text.txt') as file:
for line in file:
# do whatever you want with the line
The file object is iterable over the lines in the file - for a text file.
All you need to do is split the file after reading and you get the list of each line.
with open("text.txt", 'r') as file:
a = file.read()
a.split('\n')
With the above help, and using read rather than readlines, I was able to separate out individual lines from a file as follows:
with open("fewwords.txt", "r") as file:
a = file.read()
empty_list = []
# break a, which is read in as 1 really big string, into lines, then remove newline char
a = a.split('\n')
for i in range(len(a)):
initial_list.append(a[i])
I have an input file (File A) as shown below:
Start of the program
This is my first program ABCDE
End of the program
I receive the program name 'PYTHON' as input, and I need to replace 'ABCDE' with it. So I read the file to find the word 'program' and then replace the string after it as shown below. I have done that in my program. Then, I would like to write the updated string to the original file without changing lines 1 or 3 - just line 2.
Start of the program
This is my first program PYTHON
End of the program
My code:
fileName1 = open(filePath1, "r")
search = "program"
for line in fileName1:
if search in line:
line = line.split(" ")
update = line[5].replace(line[5], input)
temp = " ".join(line[:5]) + " " + update
fileName1 = open(filePath1, "r+")
fileName1.write(temp)
fileName1.close()
else:
fileName1 = open(filePath1, "w+")
fileName1.write(line)
fileName1.close()
I am sure this can be done in an elegant way, but I got a little confused with reading and writing as I experimented with the above code. The output is not as expected. What is wrong with my code?
You can do this with a simple replace:
file_a.txt
Start of the program`
This is my first program ABCDE`
End of the program`
code:
with open('file_a.txt', 'r') as file_handle:
file_content = file_handle.read()
orig_str = 'ABCDE'
rep_str = 'PYTHON'
result = file_content.replace(orig_str, rep_str)
# print(result)
with open('file_a.txt', 'w') as file_handle:
file_handle.write(result)
Also if just replacing ABCDE is not going to work (it may appear in other parts of file as well), then you can use more specific patterns or even a regular expression to replace it more accurately.
For example, here we just replace ABCDE if it comes after program:
with open('file_a.txt', 'r') as file_handle:
file_content = file_handle.read()
orig_str = 'ABCDE'
rep_str = 'PYTHON'
result = file_content.replace('program {}'.format(orig_str),
'program {}'.format(rep_str))
# print(result)
with open('file_a.txt', 'w') as file_handle:
file_handle.write(result)
I am writing a python script in order to write a tex file. But I had to use some information from another file. Such file has names of menus in each line that I need to use. I use split to have a list for each line of my "menu".
For example, I had to write a section with the each second element of my lists but after running, I got anything, what could I do?
This is roughly what I am doing:
texfile = open(outputtex.tex', 'w')
infile = open(txtfile.txt, 'r')
for line in infile.readlines():
linesplit = line.split('^')
for i in range(1,len(infile.readlines())):
texfile.write('\section{}\n'.format(linesplit[1]))
texfile.write('\\begin{figure*}[h!]\n')
texfile.write('\centering\n')
texfile.write('\includegraphics[scale=0.95]{pg_000%i.pdf}\n' %i)
texfile.write('\end{figure*}\n')
texfile.write('\\newpage\n')
texfile.write('\end{document}')
texfile.close()
By the way, in the inclugraphics line, I had to increace the number after pg_ from "0001" to "25050". Any clues??
I really appreciate your help.
I don't quite follow your question. But I see several errors in your code. Most importantly:
for line in infile.readlines():
...
...
for i in range(1,len(infile.readlines())):
Once you read a file, it's gone. (You can get it back, but in this case there's no point.) That means that the second call to readlines is yielding nothing, so len(infile.readlines()) == 0. Assuming what you've written here really is what you want to do (i.e. write file_len * (file_len - 1) + 1 lines?) then perhaps you should save the file to a list. Also, you didn't put quotes around your filenames, and your indentation is strange. Try this:
with open('txtfile.txt', 'r') as infile: # (with automatically closes infile)
in_lines = infile.readlines()
in_len = len(in_lines)
texfile = open('outputtex.tex', 'w')
for line in in_lines:
linesplit = line.split('^')
for i in range(1, in_len):
texfile.write('\section{}\n'.format(linesplit[1]))
texfile.write('\\begin{figure*}[h!]\n')
texfile.write('\centering\n')
texfile.write('\includegraphics[scale=0.95]{pg_000%i.pdf}\n' %i)
texfile.write('\end{figure*}\n')
texfile.write('\\newpage\n')
texfile.write('\end{document}')
texfile.close()
Perhaps you don't actually want nested loops?
infile = open('txtfile.txt', 'r')
texfile = open('outputtex.tex', 'w')
for line_number, line in enumerate(infile):
linesplit = line.split('^')
texfile.write('\section{{{0}}}\n'.format(linesplit[1]))
texfile.write('\\begin{figure*}[h!]\n')
texfile.write('\centering\n')
texfile.write('\includegraphics[scale=0.95]{pg_000%i.pdf}\n' % line_number)
texfile.write('\end{figure*}\n')
texfile.write('\\newpage\n')
texfile.write('\end{document}')
texfile.close()
infile.close()