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insert content in a specific place inside an existing file python

I am trying to append the parameters passed to a function to a specific place in an existing text file.
txt file:
query{
text:"",
source_language:"",
target_language:"",
},
data_type:[16],
params{
client:"xyz"
}
python:
def function(text,source_language,target_language):
f = open("file.txt", "w");
f.write( 'text:' + text + '\n' )
f.write( 'source_language:' + source_language + '\n' )
f.write( 'target_language:' + target_language + '\n' )
f.close()
But, its not working. Is there a way to append the parameters directly into the file including " " and ,. I am trying to add just the parameters into the existing file with data at the specified position.

Solution
In revision to your comments, considering that this is only being applied to the example above and need only to alter those specific three lines, this will accomplish the task (included if location: in case you don't match keyword it won't erase your file by open('w')
def change_text(new_text):
content[1] = list(content[1])
y = list(new_text)
content[1] = content[1][:6] + y + content[1][-2:]
content[1] = ''.join(content[1])
def change_source_l(new_source_l):
content[2] = list(content[2])
y = list(new_source_l)
content[2] = content[2][:17] + y + content[2][-2:]
content[2] = ''.join(content[2])
def change_target_l(new_target_l):
content[3] = list(content[3])
y = list(new_target_l)
content[3] = content[3][:17] + y + content[3][-2:]
content[3] = ''.join(content[3])
filename = open('query.txt', 'r')
content = filename.read()
content = content.split()
filename.close()
name = open('query.txt', 'w')
change_text('something')
change_source_l('this')
change_target_l('that')
name.write('\n'.join(content))
name.close()
Output
(xenial)vash#localhost:~/python/LPTHW$ cat query.txt
query{
text:"something",
source_language:"this",
target_language:"that",
},
data_type:[16],
params{
client:"xyz"

Open file in r+ mode
Use .seek method from Python file I/O and then write your content.

Python reading data from input file

I want to read specific data from an input file. How can I read it?
For example my file has data like:
this is my first line
this is my second line.
So I just want to read first from the first line and secon from the second line.

Try the following code for your needs but please read the comments above.
# ----------------------------------------
# open text file and write reduced lines
# ----------------------------------------
#this is my first line
#this is my second line.
pathnameIn = "D:/_working"
filenameIn = "foobar.txt"
pathIn = pathnameIn + "/" + filenameIn
pathnameOut = "D:/_working"
filenameOut = "foobar_reduced.txt"
pathOut = pathnameOut + "/" + filenameOut
fileIn = open(pathIn,'r')
fileOut = open(pathOut,'w')
print(fileIn)
print(fileOut)
i = 0
# Save all reduced lines to a file.
for lineIn in fileIn.readlines():
i += 1 # number of lines read
lineOut = lineIn[11:16]
fileOut.writelines(lineOut +"\n")
print("*********************************")
print("gelesene Zeilen: " + str(i))
print("*********************************")
fileIn.close()
fileOut.close()

Increment file name while writing file in Python

My code works and increments filename but only for two first files, after that it creates new strings in existing second file. Please help me upgrade code to increment go further.
text = 'some text'
file_path = '/path/to/file'
filename = 'textfile'
i = 1
txtfile = self.file_path + filename + str(i) + '.txt'
if not os.path.exists(txtfile):
text_file = open(txtfile, "a")
text_file.write(self.text)
text_file.close()
elif os.path.exists(txtfile) and i >= 1:
i += 1
text_file1 = open(self.file_path + filename + str(i) + '.txt', "a")
text_file1.write(self.text)
text_file1.close()

If your example is part of a loop, your resetting i to 1 in every iteration. Put the i=1 outside of this part.
And it will also start at 1 when you restart your program - sometimes not what you want.

Copy a file to a new location and increment filename, python

I am trying to:
Loop through a bunch of files
makes some changes
Copy the old file to a sub directory. Here's the kicker I don't want to overwrite the file in the new directory if it already exists. (e.g. if "Filename.mxd" already exists, then copy and rename to "Filename_1.mxd". If "Filename_1.mxd" exists, then copy the file as "Filename_2.mxd" and so on...)
save the file (but do a save, not a save as so that it overwrites the existing file)
it goes something like this:
for filename in glob.glob(os.path.join(folderPath, "*.mxd")):
fullpath = os.path.join(folderPath, filename)
mxd = arcpy.mapping.MapDocument(filename)
if os.path.isfile(fullpath):
basename, filename2 = os.path.split(fullpath)
# Make some changes to my file here
# Copy the in memory file to a new location. If the file name already exists, then rename the file with the next instance of i (e.g. filename + "_" + i)
for i in range(50):
if i > 0:
print "Test1"
if arcpy.Exists(draftloc + "\\" + filename2) or arcpy.Exists(draftloc + "\\" + shortname + "_" + str(i) + extension):
print "Test2"
pass
else:
print "Test3"
arcpy.Copy_management(filename2, draftloc + "\\" + shortname + "_" + str(i) + extension)
mxd.save()
So, 2 things I decided to do, was to just set the range of files well beyond what I expect to ever occur (50). I'm sure there's a better way of doing this, by just incrementing to the next number without setting a range.
The second thing, as you may see, is that the script saves everything in the range. I just want to save it once on the next instance of i that does not occur.
Hope this makes sense,
Mike

Use a while loop instead of a for loop. Use the while loop to find the appropriate i, and then save afterwards.
The code/pseudocode would look like:
result_name = original name
i = 0
while arcpy.Exists(result_name):
i+=1
result_name = draftloc + "\\" + shortname + "_" + str(i) + extension
save as result_name
This should fix both issues.

thanks to Maty suggestion above, I've come up with my answer. For those who are interested, my code is:
result_name = filename2
print result_name
i = 0
# Check if file exists
if arcpy.Exists(draftloc + "\\" + result_name):
# If it does, increment i by 1
i+=1
# While each successive filename (including i) does not exists, then save the next filename
while not arcpy.Exists(draftloc + "\\" + shortname + "_" + str(i) + extension):
mxd.saveACopy(draftloc + "\\" + shortname + "_" + str(i) + extension)
# else if the original file didn't satisfy the if, the save it.
else:
mxd.saveACopy(draftloc + "\\" + result_name)

Python: File Writing Adding Unintentional Newlines on Linux Only

I am using Python 2.7.9. I'm working on a program that is supposed to produce the following output in a .csv file per loop:
URL,number
Here's the main loop of the code I'm using:
csvlist = open(listfile,'w')
f = open(list, "r")
def hasQuality(item):
for quality in qualities:
if quality in item:
return True
return False
for line in f:
line = line.split('\n')
line = line[0]
# print line
itemname = urllib.unquote(line).decode('utf8')
# print itemhash
if hasQuality(itemname):
try:
looptime = time.time()
url = baseUrl + line
results = json.loads(urlopen(url).read())
# status = results.status_code
content = results
if 'median_price' in content:
medianstr = str(content['median_price']).replace('$','')
medianstr = medianstr.replace('.','')
median = float(medianstr)
volume = content['volume']
print url+'\n'+itemname
print 'Median: $'+medianstr
print 'Volume: '+str(volume)
if (median > minprice) and (volume > minvol):
csvlist.write(line + ',' + medianstr + '\n')
print '+ADDED TO LIST'
else:
print 'No median price given for '+itemname+'.\nGiving up on item.'
print "Finished loop in " + str(round(time.time() - looptime,3)) + " seconds."
except ValueError:
print "we blacklisted fool?? cause we skippin beats"
else:
print itemname+'is a commodity.\nGiving up on item.'
csvlist.close()
f.close()
print "Finished script in " + str(round(time.time() - runtime, 3)) + " seconds."
It should be generating a list that looks like this:
AWP%20%7C%20Asiimov%20%28Field-Tested%29,3911
M4A1-S%20%7C%20Hyper%20Beast%20%28Field-Tested%29,4202
But it's actually generating a list that looks like this:
AWP%20%7C%20Asiimov%20%28Field-Tested%29
,3911
M4A1-S%20%7C%20Hyper%20Beast%20%28Field-Tested%29
,4202
Whenever it is ran on a Windows machine, I have no issue. Whenever I run it on my EC2 instance, however, it adds that extra newline. Any ideas why? Running commands on the file like
awk 'NR%2{printf $0" ";next;}1' output.csv
do not do anything. I have transferred it to my Windows machine and it still reads the same. However, when I paste the output into Steam's chat client it concatenates it in the way that I want.
Thanks in advance!

This is where the problem occurs
code:
csvlist.write(line + ',' + medianstr + '\n')
This can be cleared is you strip the space
modified code:
csvlist.write(line.strip() + ',' + medianstr + '\n')
Problem:
The problem is due to the fact you are reading raw lines from the input file
Raw_lines contain \n to indicate there is a new line for every line which is not the last and for the last line it just ends with the given character .
for more details:
Just type print(repr(line)) before writing and see the output