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Python list iterate not working as expected

I have a file called list.txt:
['d1','d2','d3']
I want to loop through all the items in the list. Here is the code:
deviceList = open("list.txt", "r")
deviceList = deviceList.read()
for i in deviceList:
print(i)
Here the issue is that, when I run the code, it will split all the characters:
% python3 run.py
[
'
d
1
'
,
'
d
2
'
,
'
d
3
'
]
It's like all the items have been considered as 1 string? I think needs to be parsed? Please let me know what am I missing..

Simply because you do not have a list, you are reading a pure text...
I suggest writing the list without the [] so you can use the split() function.
Write the file like this: d1;d2;d3
and use this script to obtain a list
f = open("filename", 'r')
line = f.readlines()
f.close()
list = line.split(";")
if you need the [] in the file, simply add a strip() function like this
f = open("filename", 'r')
line = f.readlines()
f.close()
strip = line.strip("[]")
list = strip.split(";")
should work the same

This isn't the cleanest solution, but it will do if your .txt file is always just in the "[x,y,z]" format.
deviceList = open("list.txt", "r")
deviceList = deviceList[1:-1]
deviceList = deviceList.split(",")
for i in deviceList:
print(i)
This takes your string, strips the "[" and "]", and then separates the entire string between the commas and turns that into a list. As other users have suggested, there are probably better ways to store this list than a text file as it is, but this solution will do exactly what you are asking. Hope this helps!

Python Make newline after character

I would like to make a newline after a dot in a file.
For example:
Hello. I am damn cool. Lol
Output:
Hello.
I am damn cool.
Lol
I tried it like that, but somehow it's not working:
f2 = open(path, "w+")
for line in f2.readlines():
f2.write("\n".join(line))
f2.close()
Could your help me there?
I want not just a newline, I want a newline after every dot in a single file. It should iterate through the whole file and make newlines after every single dot.
Thank you in advance!

This should be enough to do the trick:
with open('file.txt', 'r') as f:
contents = f.read()
with open('file.txt', 'w') as f:
f.write(contents.replace('. ', '.\n'))

You could split your string based on . and store in a list, then just print out the list.
s = 'Hello. I am damn cool. Lol'
lines = s.split('.')
for line in lines:
print(line)
If you do this, the output will be:
Hello
I am damn cool
Lol
To remove leading spaces, you could split based on . (with a space), or else use lstrip() when printing.
So, to do this for a file:
# open file for reading
with open('file.txt') as fr:
# get the text in the file
text = fr.read()
# split up the file into lines based on '.'
lines = text.split('.')
# open the file for writing
with open('file.txt', 'w') as fw:
# loop over each line
for line in lines:
# remove leading whitespace, and write to the file with a newline
fw.write(line.lstrip() + '\n')

reading in file python says its a string [duplicate]

I have a text file that looks like:
ABC
DEF
How can I read the file into a single-line string without newlines, in this case creating a string 'ABCDEF'?
For reading the file into a list of lines, but removing the trailing newline character from each line, see How to read a file without newlines?.

You could use:
with open('data.txt', 'r') as file:
data = file.read().replace('\n', '')
Or if the file content is guaranteed to be one-line
with open('data.txt', 'r') as file:
data = file.read().rstrip()

In Python 3.5 or later, using pathlib you can copy text file contents into a variable and close the file in one line:
from pathlib import Path
txt = Path('data.txt').read_text()
and then you can use str.replace to remove the newlines:
txt = txt.replace('\n', '')

You can read from a file in one line:
str = open('very_Important.txt', 'r').read()
Please note that this does not close the file explicitly.
CPython will close the file when it exits as part of the garbage collection.
But other python implementations won't. To write portable code, it is better to use with or close the file explicitly. Short is not always better. See https://stackoverflow.com/a/7396043/362951

To join all lines into a string and remove new lines, I normally use :
with open('t.txt') as f:
s = " ".join([l.rstrip("\n") for l in f])

with open("data.txt") as myfile:
data="".join(line.rstrip() for line in myfile)
join() will join a list of strings, and rstrip() with no arguments will trim whitespace, including newlines, from the end of strings.

This can be done using the read() method :
text_as_string = open('Your_Text_File.txt', 'r').read()
Or as the default mode itself is 'r' (read) so simply use,
text_as_string = open('Your_Text_File.txt').read()

I'm surprised nobody mentioned splitlines() yet.
with open ("data.txt", "r") as myfile:
data = myfile.read().splitlines()
Variable data is now a list that looks like this when printed:
['LLKKKKKKKKMMMMMMMMNNNNNNNNNNNNN', 'GGGGGGGGGHHHHHHHHHHHHHHHHHHHHEEEEEEEE']
Note there are no newlines (\n).
At that point, it sounds like you want to print back the lines to console, which you can achieve with a for loop:
for line in data:
print(line)

It's hard to tell exactly what you're after, but something like this should get you started:
with open ("data.txt", "r") as myfile:
data = ' '.join([line.replace('\n', '') for line in myfile.readlines()])

I have fiddled around with this for a while and have prefer to use use read in combination with rstrip. Without rstrip("\n"), Python adds a newline to the end of the string, which in most cases is not very useful.
with open("myfile.txt") as f:
file_content = f.read().rstrip("\n")
print(file_content)

Here are four codes for you to choose one:
with open("my_text_file.txt", "r") as file:
data = file.read().replace("\n", "")
or
with open("my_text_file.txt", "r") as file:
data = "".join(file.read().split("\n"))
or
with open("my_text_file.txt", "r") as file:
data = "".join(file.read().splitlines())
or
with open("my_text_file.txt", "r") as file:
data = "".join([line for line in file])

you can compress this into one into two lines of code!!!
content = open('filepath','r').read().replace('\n',' ')
print(content)
if your file reads:
hello how are you?
who are you?
blank blank
python output
hello how are you? who are you? blank blank

You can also strip each line and concatenate into a final string.
myfile = open("data.txt","r")
data = ""
lines = myfile.readlines()
for line in lines:
data = data + line.strip();
This would also work out just fine.

This is a one line, copy-pasteable solution that also closes the file object:
_ = open('data.txt', 'r'); data = _.read(); _.close()

f = open('data.txt','r')
string = ""
while 1:
line = f.readline()
if not line:break
string += line
f.close()
print(string)

python3: Google "list comprehension" if the square bracket syntax is new to you.
with open('data.txt') as f:
lines = [ line.strip('\n') for line in list(f) ]

Oneliner:
List: "".join([line.rstrip('\n') for line in open('file.txt')])
Generator: "".join((line.rstrip('\n') for line in open('file.txt')))
List is faster than generator but heavier on memory. Generators are slower than lists and is lighter for memory like iterating over lines. In case of "".join(), I think both should work well. .join() function should be removed to get list or generator respectively.
Note: close() / closing of file descriptor probably not needed

Have you tried this?
x = "yourfilename.txt"
y = open(x, 'r').read()
print(y)

To remove line breaks using Python you can use replace function of a string.
This example removes all 3 types of line breaks:
my_string = open('lala.json').read()
print(my_string)
my_string = my_string.replace("\r","").replace("\n","")
print(my_string)
Example file is:
{
"lala": "lulu",
"foo": "bar"
}
You can try it using this replay scenario:
https://repl.it/repls/AnnualJointHardware

I don't feel that anyone addressed the [ ] part of your question. When you read each line into your variable, because there were multiple lines before you replaced the \n with '' you ended up creating a list. If you have a variable of x and print it out just by
x
or print(x)
or str(x)
You will see the entire list with the brackets. If you call each element of the (array of sorts)
x[0]
then it omits the brackets. If you use the str() function you will see just the data and not the '' either.
str(x[0])

Maybe you could try this? I use this in my programs.
Data= open ('data.txt', 'r')
data = Data.readlines()
for i in range(len(data)):
data[i] = data[i].strip()+ ' '
data = ''.join(data).strip()

Regular expression works too:
import re
with open("depression.txt") as f:
l = re.split(' ', re.sub('\n',' ', f.read()))[:-1]
print (l)
['I', 'feel', 'empty', 'and', 'dead', 'inside']

with open('data.txt', 'r') as file:
data = [line.strip('\n') for line in file.readlines()]
data = ''.join(data)

from pathlib import Path
line_lst = Path("to/the/file.txt").read_text().splitlines()
Is the best way to get all the lines of a file, the '\n' are already stripped by the splitlines() (which smartly recognize win/mac/unix lines types).
But if nonetheless you want to strip each lines:
line_lst = [line.strip() for line in txt = Path("to/the/file.txt").read_text().splitlines()]
strip() was just a useful exemple, but you can process your line as you please.
At the end, you just want concatenated text ?
txt = ''.join(Path("to/the/file.txt").read_text().splitlines())

This works:
Change your file to:
LLKKKKKKKKMMMMMMMMNNNNNNNNNNNNN GGGGGGGGGHHHHHHHHHHHHHHHHHHHHEEEEEEEE
Then:
file = open("file.txt")
line = file.read()
words = line.split()
This creates a list named words that equals:
['LLKKKKKKKKMMMMMMMMNNNNNNNNNNNNN', 'GGGGGGGGGHHHHHHHHHHHHHHHHHHHHEEEEEEEE']
That got rid of the "\n". To answer the part about the brackets getting in your way, just do this:
for word in words: # Assuming words is the list above
print word # Prints each word in file on a different line
Or:
print words[0] + ",", words[1] # Note that the "+" symbol indicates no spaces
#The comma not in parentheses indicates a space
This returns:
LLKKKKKKKKMMMMMMMMNNNNNNNNNNNNN, GGGGGGGGGHHHHHHHHHHHHHHHHHHHHEEEEEEEE

with open(player_name, 'r') as myfile:
data=myfile.readline()
list=data.split(" ")
word=list[0]
This code will help you to read the first line and then using the list and split option you can convert the first line word separated by space to be stored in a list.
Than you can easily access any word, or even store it in a string.
You can also do the same thing with using a for loop.

file = open("myfile.txt", "r")
lines = file.readlines()
str = '' #string declaration
for i in range(len(lines)):
str += lines[i].rstrip('\n') + ' '
print str

Try the following:
with open('data.txt', 'r') as myfile:
data = myfile.read()
sentences = data.split('\\n')
for sentence in sentences:
print(sentence)
Caution: It does not remove the \n. It is just for viewing the text as if there were no \n

Modify a string in a text file

In a file I have a names of planets:
sun moon jupiter saturn uranus neptune venus
I would like to say "replace saturn with sun". I have tried to write it as a list. I've tried different modes (write, append etc.)
I think I am struggling to understand the concept of iteration, especially when it comes to iterating over a list, dict, or str in file. I know it can be done using csv or json or even pickle module. But my objective is to get the grasp of iteration using for...loop to modify a txt file. And I want to do that using .txt file only.
with open('planets.txt', 'r+')as myfile:
for line in myfile.readlines():
if 'saturn' in line:
a = line.replace('saturn', 'sun')
myfile.write(str(a))
else:
print(line.strip())

Try this but keep in mind if you use string.replace method it will replace for example testsaturntest to testsuntest, you should use regex instead:
In [1]: cat planets.txt
saturn
In [2]: s = open("planets.txt").read()
In [3]: s = s.replace('saturn', 'sun')
In [4]: f = open("planets.txt", 'w')
In [5]: f.write(s)
In [6]: f.close()
In [7]: cat planets.txt
sun

This replaces the data in the file with the replacement you want and prints the values out:
with open('planets.txt', 'r+') as myfile:
lines = myfile.readlines()
modified_lines = map(lambda line: line.replace('saturn', 'sun'), lines)
with open('planets.txt', 'w') as f:
for line in modified_lines:
f.write(line)
print(line.strip())
Replacing the lines in-file is quite tricky, so instead I read the file, replaced the files and wrote them back to the file.

If you just want to replace the word in the file, you can do it like this:
import re
lines = open('planets.txt', 'r').readlines()
newlines = [re.sub(r'\bsaturn\b', 'sun', l) for l in lines]
open('planets.txt', 'w').writelines(newlines)

f = open("planets.txt","r+")
lines = f.readlines() #Read all lines
f.seek(0, 0); # Go to first char position
for line in lines: # get a single line
f.write(line.replace("saturn", "sun")) #replace and write
f.close()
I think its a clear guide :) You can find everything for this.

I have not tested your code but the issue with r+ is that you need to keep track of where you are in the file so that you can reset the file position so that you replace the current line instead of writing the replacement afterwords. I suggest creating a variable to keep track of where you are in the file so that you can call myfile.seek()

Splitting lines in python based on some character

Input:
!,A,56281,12/12/19,19:34:12,000.0,0,37N22.714,121W55.576,+0013!,A,56281,12/1
2/19,19:34:13,000.0,0,37N22.714,121W55.576,+0013!,A,56281,12/12/19,19:34:14,000.
0,0,37N22.714,121W55.576,+0013!,A,56281,12/12/19,19:34:15,000.0,0,37N22.714,121W
55.576,+0013!,A,56281,12/12/19,19:34:16,000.0,0,37N22.714,121W55.576,+0013!,A,56
281,12/12/19,19:34:17,000.0,0,37N22.714,121W55.576,+0013!,A,56281,12/12/19,19:34
:18,000.0,0,37N22.714,121W55.576,+0013!,A,56281,12/12/19,19:34:19,000.0,0,37N22.
Output:
!,A,56281,12/12/19,19:34:12,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:13,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:14,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:15,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:16,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:17,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:18,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:19,000.0,0,37N22.
'!' is the starting character and +0013 should be the ending of each line (if present).
Problem which I am getting:
Output is like :
!,A,56281,12/12/19,19:34:12,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/1
2/19,19:34:13,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:14,000.
0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:15,000.0,0,37N22.714,121W
Any help would be highly appreciated...!!!
My code:
file_open= open('sample.txt','r')
file_read= file_open.read()
file_open2= open('output.txt','w+')
counter =0
for i in file_read:
if '!' in i:
if counter == 1:
file_open2.write('\n')
counter= counter -1
counter= counter +1
file_open2.write(i)

You can try something like this:
with open("abc.txt") as f:
data=f.read().replace("\r\n","") #replace the newlines with ""
#the newline can be "\n" in your system instead of "\r\n"
ans=filter(None,data.split("!")) #split the data at '!', then filter out empty lines
for x in ans:
print "!"+x #or write to some other file
.....:
!,A,56281,12/12/19,19:34:12,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:13,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:14,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:15,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:16,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:17,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:18,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:19,000.0,0,37N22.

Could you just use str.split?
lines = file_read.split('!')
Now lines is a list which holds the split data. This is almost the lines you want to write -- The only difference is that they don't have trailing newlines and they don't have '!' at the start. We can put those in easily with string formatting -- e.g. '!{0}\n'.format(line). Then we can put that whole thing in a generator expression which we'll pass to file.writelines to put the data in a new file:
file_open2.writelines('!{0}\n'.format(line) for line in lines)
You might need:
file_open2.writelines('!{0}\n'.format(line.replace('\n','')) for line in lines)
if you find that you're getting more newlines than you wanted in the output.
A few other points, when opening files, it's nice to use a context manager -- This makes sure that the file is closed properly:
with open('inputfile') as fin:
lines = fin.read()
with open('outputfile','w') as fout:
fout.writelines('!{0}\n'.format(line.replace('\n','')) for line in lines)

Another option, using replace instead of split, since you know the starting and ending characters of each line:
In [14]: data = """!,A,56281,12/12/19,19:34:12,000.0,0,37N22.714,121W55.576,+0013!,A,56281,12/1
2/19,19:34:13,000.0,0,37N22.714,121W55.576,+0013!,A,56281,12/12/19,19:34:14,000.
0,0,37N22.714,121W55.576,+0013!,A,56281,12/12/19,19:34:15,000.0,0,37N22.714,121W
55.576,+0013!,A,56281,12/12/19,19:34:16,000.0,0,37N22.714,121W55.576,+0013!,A,56
281,12/12/19,19:34:17,000.0,0,37N22.714,121W55.576,+0013!,A,56281,12/12/19,19:34
:18,000.0,0,37N22.714,121W55.576,+0013!,A,56281,12/12/19,19:34:19,000.0,0,37N22.""".replace('\n', '')
In [15]: print data.replace('+0013!', "+0013\n!")
!,A,56281,12/12/19,19:34:12,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:13,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:14,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:15,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:16,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:17,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:18,000.0,0,37N22.714,121W55.576,+0013
!,A,56281,12/12/19,19:34:19,000.0,0,37N22.

Just for some variance, here is a regular expression answer:
import re
outputFile = open('output.txt', 'w+')
with open('sample.txt', 'r') as f:
for line in re.findall("!.+?(?=!|$)", f.read(), re.DOTALL):
outputFile.write(line.replace("\n", "") + '\n')
outputFile.close()
It will open the output file, get the contents of the input file, and loop through all the matches using the regular expression !.+?(?=!|$) with the re.DOTALL flag. The regular expression explanation & what it matches can be found here: http://regex101.com/r/aK6aV4
After we have a match, we strip out the new lines from the match, and write it to the file.

Let's try to add a \n before every "!"; then let python splitlines :-) :
file_read.replace("!", "!\n").splitlines()

I will actually implement as a generator so that you can work on the data stream rather than the entire content of the file. This will be quite memory friendly if working with huge files
>>> def split_on_stream(it,sep="!"):
prev = ""
for line in it:
line = (prev + line.strip()).split(sep)
for parts in line[:-1]:
yield parts
prev = line[-1]
yield prev
>>> with open("test.txt") as fin:
for parts in split_on_stream(fin):
print parts
,A,56281,12/12/19,19:34:12,000.0,0,37N22.714,121W55.576,+0013
,A,56281,12/12/19,19:34:13,000.0,0,37N22.714,121W55.576,+0013
,A,56281,12/12/19,19:34:14,000.0,0,37N22.714,121W55.576,+0013
,A,56281,12/12/19,19:34:15,000.0,0,37N22.714,121W55.576,+0013
,A,56281,12/12/19,19:34:16,000.0,0,37N22.714,121W55.576,+0013
,A,56281,12/12/19,19:34:17,000.0,0,37N22.714,121W55.576,+0013
,A,56281,12/12/19,19:34:18,000.0,0,37N22.714,121W55.576,+0013
,A,56281,12/12/19,19:34:19,000.0,0,37N22.