I have a wordlist that contains returns to separate each new letter. Is there a way to programatically delete each of these returns using file I/O in Python?
Edit: I know how to manipulate strings to delete returns. I want to physically edit the file so that those returns are deleted.
I'm looking for something like this:
wfile = open("wordlist.txt", "r+")
for line in wfile:
if len(line) == 0:
# note, the following is not real... this is what I'm aiming to achieve.
wfile.delete(line)
>>> string = "testing\n"
>>> string
'testing\n'
>>> string = string[:-1]
>>> string
'testing'
This basically says "chop off the last thing in the string" The : is the "slice" operator. It would be a good idea to read up on how it works as it is very useful.
EDIT
I just read your updated question. I think I understand now. You have a file, like this:
aqua:test$ cat wordlist.txt
Testing
This
Wordlist
With
Returns
Between
Lines
and you want to get rid of the empty lines. Instead of modifying the file while you're reading from it, create a new file that you can write the non-empty lines from the old file into, like so:
# script
rf = open("wordlist.txt")
wf = open("newwordlist.txt","w")
for line in rf:
newline = line.rstrip('\r\n')
wf.write(newline)
wf.write('\n') # remove to leave out line breaks
rf.close()
wf.close()
You should get:
aqua:test$ cat newwordlist.txt
Testing
This
Wordlist
With
Returns
Between
Lines
If you want something like
TestingThisWordlistWithReturnsBetweenLines
just comment out
wf.write('\n')
You can use a string's rstrip method to remove the newline characters from a string.
>>> 'something\n'.rstrip('\r\n')
>>> 'something'
The most efficient is to not specify a strip value
'\nsomething\n'.split() will strip all special characters and whitespace from the string
simply use, it solves the issue.
string.strip("\r\n")
Remove empty lines in the file:
#!/usr/bin/env python
import fileinput
for line in fileinput.input("wordlist.txt", inplace=True):
if line != '\n':
print line,
The file is moved to a backup file and standard output is directed to the input file.
'whatever\r\r\r\r\r\r\r\r\n\n\n\n\n'.translate(None, '\r\n')
returns
'whatever'
This is also a possible solution
file1 = open('myfile.txt','r')
conv_file = open("numfile.txt","w")
temp = file1.read().splitlines()
for element in temp:
conv_file.write(element)
file1.close()
conv_file.close()
Related
I am writing a list (simple[]) to a file using writelines() and I need each item from the list to be on a new line in the file. I am using the following code:
file_path_simple = r'[path_redacted]\tx_list_simple.txt'
with open(file_path_simple, 'w') as fp:
for i in simple:
#ignores any blank lines
if i == '':
continue
else:
fp.writelines([i])
fp.writelines('\n')
fp.close()
The problem I am having is that when read from the file later it includes the \n, so instead of python reading:
blablabla
it reads:
blablabla\n
How can I make it not read the \n? Or do I need to use something like re.split() to remove the \n prior to reading?
This seems like something really simple I am overlooking.
You can use rstrip.
i = i.rstrip('\n')
I am still learning python and have a question about the function readlines() The following is a part of my script:
f = open("demofile.txt", "r")
text = "".join(f.readlines())
print(text)
demofile.txt contains:
This is the first line
This is the second line
This is the third line
Now I want to add a single word to this so I get:
This is the first line
This is the second line
This is the third line
Example
I thought of something easy way of doing it:
f = open("demofile.txt", "r")
text = "".join(f.readlines())."Example"
print(text)
But that doesn't work (of course) I googled and looked around here but didn't really have the good keywords to search for this issue. Hopefully someone can point me in the right direction.
.readlines() returns list you can append() to it:
with open("demofile.txt") as txt:
lines = txt.readlines()
lines.append("Example")
text = "".join(lines)
print(text)
or you can unpack the file object txt, since its an iterator to a new list with the word you wanted to add:
with open("demofile.txt") as txt:
text = "".join([*txt, "Example"])
print(text)
Firstly, the open function in python opens a file in read mode by default. Thus, you do not need to specify the mode r when opening the file. Secondly, you should always close a file after you are done with it. A with statement in python handles this for you. Moreover, instead of using . to add Example onto the end of the string, you should use the concatenation operator in python to add a newline character, \n, and the string, Example.
with open("demofile.txt") as f:
text = "".join(f.readlines()) + "\nExample"
print(text)
This should help you. While dealing with files. It is always recommended to use with open('filename','r') as f instead of f=open('filename','r'). Using ContextManager during file open is the idea that this file will be open in any case whether everything is ok or any exception is raised. And you don't need to explicitly close the file i.e f.close().
end_text='Example'
with open('test.txt','r') as f:
text=''.join(f.readlines())+'\n'+end_text
print(text)
I am writing in python 3.6 and am having trouble making my code match strings in a short text document. this is a simple example of the exact logic that is breaking my bigger program:
PATH = "C:\\Users\\JoshLaptop\\PycharmProjects\\practice\\commented.txt"
file = open(PATH, 'r')
words = ['bah', 'dah', 'gah', "fah", 'mah']
print(file.read().splitlines())
if 'bah' not in file.read().splitlines():
print("fail")
with the text document formatted like so:
bah
gah
fah
dah
mah
and it is indeed printing out fail each time I run this. Am I using the incorrect method of reading the data from the text document?
the issue is that you're printing print(file.read().splitlines())
so it exhausts the file, and the next call to file.read().splitlines() returns an empty list...
A better way to "grep" your pattern would be to iterate on the file lines instead of reading it fully. So if you find the string early in the file, you save time:
with open(PATH, 'r') as f:
for line in f:
if line.rstrip()=="bah":
break
else:
# else is reached when no break is called from the for loop: fail
print("fail")
The small catch here is not to forget to call line.rstrip() because file generator issues the line with the line terminator. Also, if there's a trailing space in your file, this code will still match the word (make it strip() if you want to match even with leading blanks)
If you want to match a lot of words, consider creating a set of lines:
lines = {line.rstrip() for line in f}
so your in lines call will be a lot faster.
Try it:
PATH = "C:\\Users\\JoshLaptop\\PycharmProjects\\practice\\commented.txt"
file = open(PATH, 'r')
words = file.read().splitlines()
print(words)
if 'bah' not in words:
print("fail")
You can't read the file two times.
When you do print(file.read().splitlines()), the file is read and the next call to this function will return nothing because you are already at the end of file.
PATH = "your_file"
file = open(PATH, 'r')
words = ['bah', 'dah', 'gah', "fah", 'mah']
if 'bah' not in (file.read().splitlines()) :
print("fail")
as you can see output is not 'fail' you must use one 'file.read().splitlines()' in code or save it in another variable otherwise you have an 'fail' message
I have a text file like below:
/john
/peter
/Sam
/Jennefer
Using the the following script:
keyword_file = open(text_file)
j = keyword_file.readlines()
for i in range(len(j)):
if j[i] == "/peter":
print "yes"
although /peter is in the text file I don't get the printed yes. However when I delete "/"s , "yes" is printed. What is the problem with it?
First off you're not just looking for /peter you're looking for /peter\n.
Second, there's a lot here that you can do to improve your script:
Use with instead of forcing yourself to open and close your file:
with open(text_file) as fp:
<your code here>
Instead of reading the entire file, read it line by line:
for line in fp:
<your business logic here>
compare your string using is instead of ==: See this SO answer why I'm wrong here
if line is '/peter\n':
<condition if peter is found>
Here's the combined script that match what you're trying to do:
with open(text_file) as fp:
for line in fp:
if line == '/peter\n':
print("yes") # please use print(<what you want to print here>) instead of print <what you want here> for compatibility with 3.0 and readability.
The problem here is that you are looking for an exact match on the whole line. This includes any special ascii characters that may be included; such as a newline character.
If you instead read the text, and split it by line, and iterate over the result your code would work:
result = keyword_file.read()
for line in result.split('\n'):
if line == "/peter":
print "yes"
As an alternative you could use
for line in keyword_file:
if line.startswith("/peter"): # or "/peter" in line
print "yes"
If you want to avoid storing the whole file in memory, and still have a clean if statement you can use strip() to remove any unnecessary special characters or spaces.
with open(file_name) as file_obj:
for line in file_obj:
if line.strip() == '/peter':
print "yes"
My code looks like this:
def storescores():
hs = open("hst.txt","a")
hs.write(name)
hs.close()
so if I run it and enter "Ryan"
then run it again and enter "Bob"
the file hst.txt looks like
RyanBob
instead of
Ryan
Bob
How do I fix this?
If you want a newline, you have to write one explicitly. The usual way is like this:
hs.write(name + "\n")
This uses a backslash escape, \n, which Python converts to a newline character in string literals. It just concatenates your string, name, and that newline character into a bigger string, which gets written to the file.
It's also possible to use a multi-line string literal instead, which looks like this:
"""
"""
Or, you may want to use string formatting instead of concatenation:
hs.write("{}\n".format(name))
All of this is explained in the Input and Output chapter in the tutorial.
In Python >= 3.6 you can use new string literal feature:
with open('hst.txt', 'a') as fd:
fd.write(f'\n{name}')
Please notice using 'with statment' will automatically close the file when 'fd' runs out of scope
All answers seem to work fine. If you need to do this many times, be aware that writing
hs.write(name + "\n")
constructs a new string in memory and appends that to the file.
More efficient would be
hs.write(name)
hs.write("\n")
which does not create a new string, just appends to the file.
The answer is not to add a newline after writing your string. That may solve a different problem. What you are asking is how to add a newline before you start appending your string. If you want to add a newline, but only if one does not already exist, you need to find out first, by reading the file.
For example,
with open('hst.txt') as fobj:
text = fobj.read()
name = 'Bob'
with open('hst.txt', 'a') as fobj:
if not text.endswith('\n'):
fobj.write('\n')
fobj.write(name)
You might want to add the newline after name, or you may not, but in any case, it isn't the answer to your question.
I had the same issue. And I was able to solve it by using a formatter.
file_name = "abc.txt"
new_string = "I am a new string."
opened_file = open(file_name, 'a')
opened_file.write("%r\n" %new_string)
opened_file.close()
I hope this helps.
There is also one fact that you have to consider.
You should first check if your file is empty before adding anything to it. Because if your file is empty then I don't think you would like to add a blank new line in the beginning of the file. This code
first checks if the file is empty
If the file is empty then it will simply add your input text to the file else it will add a new line and then it will add your text to the file. You should use a try catch for os.path.getsize() to catch any exceptions.
Code:
import os
def storescores():
hs = open("hst.txt","a")
if(os.path.getsize("hst.txt") > 0):
hs.write("\n"+name)
else:
hs.write(name)
hs.close()
I presume that all you are wanting is simple string concatenation:
def storescores():
hs = open("hst.txt","a")
hs.write(name + " ")
hs.close()
Alternatively, change the " " to "\n" for a newline.
import subprocess
subprocess.check_output('echo "' + YOURTEXT + '" >> hello.txt',shell=True)
f=open("Python_Programs/files_forhndling.txt","a+")
inpt=str(input("Enter anything:\n>>"))
f.write(inpt)
f.write("\n")
print("Data inserted Successfully")
f.close()
welcome to file handling
new line
file handling in python
123456
78875454
✔ Output 💡 CLICK BELOW & SEE ✔
You need to change parameter "a" => "a+".
Follow this code bellows:
def storescores():
hs = open("hst.txt","a+")