Develop Reference

Fix compared data and return line number and data

I have typed a program to compare vehicle A price (v_priceA) to various other vehicle prices in a carprices.txt text file which are in a new line.
The result should be a new text called highprices.txt file with all the prices greater than the price of Vehicle A in a newline and the associated line number from carprices.txt
My problem is am able to generate two text files that has the line number of the greater file and another with the greater price, instead of the greater price itself and line number together. I need to fix this.
Vehicle A price: 2500.50
v_priceA = 2500.50
a_file = 'carprices.txt'
with open(a_file, 'r') as document:
values = [x for x, value in enumerate(document) if float(value) > v_priceA]
new_file = open('highpriceposition.txt', 'w')
for x in values:
new_file.write(str(x) + '\n')
new_file.close()
a_file = 'carprices.txt'
with open(a_file, 'r') as document:
values = [value for value in document if float(value) > v_priceA]
with open('highprice.txt', 'w') as f:
for x in values:
f.write(str(x)+'\n')
positionprice.txt
2 2900.00
3 3500.50
5 25000.30
6 45000.50

When you write to the new file new_file.write() you need to pass it both the line number and price. I.E.
v_priceA = 2500.50
a_file = 'carprices.txt'
output_file = 'highprices.txt'
with open(a_file, 'r') as document:
with open(output_file, 'w') as new_file:
for line, price in enumerate(document):
if float(price) > v_priceA:
new_file.write(str(line) + " " + str(price))
# See how I pass both in here?
It's important to know that whenever you open() a file in python as write "w" it's going to erase whatever is in that file before writing to it. (There's an append option if your interested).
Docs for Open.
Notice how I only open the output file once in the above code? That should help.
Now on to how enumerate works. It takes an iterable object in python
and for each item in that iterable returns a tuple of (itemIndex, item) with at least one very important exception it basically the succinct equivalent of:
def myEnumerate(iterableParameter):
i = 0
outPutList = []
while i < len(iterableParameter):
outPutList += (i, iterableParameter[i])
return outPutList
The important exception is that enumerate creates a generator where as the above creates a list. See further reading.

reading a file and parse them into section

okay so I have a file that contains ID number follows by name just like this:
10 alex de souza
11 robin van persie
9 serhat akin
I need to read this file and break each record up into 2 fields the id, and the name. I need to store the entries in a dictionary where ID is the key and the name is the satellite data. Then I need to output, in 2 columns, one entry per line, all the entries in the dictionary, sorted (numerically) by ID. dict.keys and list.sort might be helpful (I guess). Finally the input filename needs to be the first command-line argument.
Thanks for your help!
I have this so far however can't go any further.
fin = open("ids","r") #Read the file
for line in fin: #Split lines
string = str.split()
if len(string) > 1: #Seperate names and grades
id = map(int, string[0]
name = string[1:]
print(id, name) #Print results

We need sys.argv to get the command line argument (careful, the name of the script is always the 0th element of the returned list).
Now we open the file (no error handling, you should add that) and read in the lines individually. Now we have 'number firstname secondname'-strings for each line in the list "lines".
Then open an empty dictionary out and loop over the individual strings in lines, splitting them every space and storing them in the temporary variable tmp (which is now a list of strings: ('number', 'firstname','secondname')).
Following that we just fill the dictionary, using the number as key and the space-joined rest of the names as value.
To print the dictionary sorted just loop over the list of numbers returned by sorted(out), using the key=int option for numerical sorting. Then print the id (the number) and then the corresponding value by calling the dictionary with a string representation of the id.
import sys
try:
infile = sys.argv[1]
except IndexError:
infile = input('Enter file name: ')
with open(infile, 'r') as file:
lines = file.readlines()
out = {}
for fullstr in lines:
tmp = fullstr.split()
out[tmp[0]] = ' '.join(tmp[1:])
for id in sorted(out, key=int):
print id, out[str(id)]
This works for python 2.7 with ASCII-strings. I'm pretty sure that it should be able to handle other encodings as well (German Umlaute work at least), but I can't test that any further. You may also want to add a lot of error handling in case the input file is somehow formatted differently.

Just a suggestion, this code is probably simpler than the other code posted:
import sys
with open(sys.argv[1], "r") as handle:
lines = handle.readlines()
data = dict([i.strip().split(' ', 1) for i in lines])
for idx in sorted(data, key=int):
print idx, data[idx]

How to fetch these below values in python

I have a file in the below format
.aaa b/b
.ddd e/e
.fff h/h
.lop m/n
I'm trying to read this file. My desired output is if I find ".aaa" I should get b/b, if I find ".ddd" I should get e/e and so on.
I know how to fetch 1st column and 2nd column but I don't know how to compare them and fetch the value. This is what I've written.
file = open('some_file.txt')
for line in file:
fields = line.strip().split()
print (fields[0]) #This will give 1st column
print (fields[1]) # This will give 2nd column
This is not the right way of doing things. What approach follow?

Any time you want to do lookups, a dictionary is going to be your friend.
You could write a function to load the data into a dictionary:
def load_data(filename):
result = dict()
with open(filename, 'r') as f:
for line in f:
k,v = line.strip().split() # will fail if not exactly 2 fields
result[k] = v
return result
And then use it to perform your lookups like this:
data = load_data('foo.txt')
print data['.aaa']

It sounds like what you may want is to build a dictionary mapping column 1 to column 2. You could try:
file = open('some_file.txt')
field_dict = {}
for line in file:
fields = line.strip().split()
field_dict[fields[0]] = fields[1]
Then in your other code, when you see '.ddd' you can simply get the reference from the dictionary (e.g. field_dict['.ddd'] should return 'e/e')

Just do splitting on each line according to the spaces and check whether the first item matches the word you gave. If so then do printing the second item from the list.
word = input("Enter the word to search : ")
with open(file) as f:
for line in f:
m = line.strip().split()
if m[0] == word:
print m[1]

Write dictionary values (list) to output file - Python

I am trying to print values(a list) from a dictionary to the third column of another file that contains the dictionary key in the first column. I would like the list of values to print in the third column of the output file with a space separating each value. I know my problem lies somewhere in the fact that Python can't write things that aren't strings and that the list is separated by a "," but I am new to programming and am not sure how to accomplish this - any help is much appreciated, thanks!
The GtfFile.txt is a 10 column file (sep = '\t') which I generate the dictionary from... using the Gene name as the key and the Term (functional category) as the values. Several genes have more than one Term attributed to them and are repeated as new lines for each term. There are varying numbers of genes associated with each Term as well and thus I generate a list as the key for each Term. THIS PART OF MY SCRIPT APPEARS TO BE WORKING AS I WOULD LIKE IT TO!
The FuncEnr_terms.txt is a 2 column file (sep ='\t') which consists of a Term in the first column and a description of the term in the 2 column. My desired output file would be to duplicate this file with a third column that contains the Genes associated with the Term separated by a space. WRITING THIS TO THE OUTPUT FILE IS WHERE MY PROBLEM LIES.
Below is my code:
#!/usr/bin/env python
import sys
from collections import defaultdict
if len(sys.argv) != 4 :
print("Usage: GeneSetFileGen.py <GtfFile.txt> <FuncEnr_terms.txt> <OutputFile.txt>")
sys.exit(0)
OutFileName = sys.argv[3]
OutFile = open(OutFileName, 'w')
TermGeneDic = defaultdict(list)
with open(sys.argv[1], 'r') as f :
for line in f :
line = line.strip()
line = line.split('\t')
Term = line[8]
Gene = line[0]
TermGeneDic[Term].append(Gene)
#write output file
with open(sys.argv[2], 'r') as f :
for line in f :
line = line.strip()
Term, Des = line.split('\t')
OutFile.write(Term + '\t' + Des + '\t' + str(TermGeneDic[Term]) + '\n')
OutFile.close

If I understand what you require correctly then what you need is to replace this expression:
str(TermGeneDic[Term])
with something like:
" ".join(TermGeneDic[Term])

A couple of pointers on your code: your code will be incomprehensible to anyone else if you don't follow pep 8 conventions fairly closely. This means, no CamelCase except for class names.
Secondly, reusing variable is generally bad, and a sign that you should just chain up those method calls. It's especially bad when you have a variable like line whose type you actually change.
Thirdly, brackets (parentheses) are mandatory for calling a method or function.
Fourthly, you join the elements of a list into a string with '\t'.join(termgenes[term])
Finally, use templating to generate long strings - it ends up being easier to work with.
Your code should look like:
import sys
from collections import defaultdict
if len(sys.argv) != 4 :
print("Usage: GeneSetFileGen.py <GtfFile.txt> <FuncEnr_terms.txt> <OutputFile.txt>")
sys.exit(0)
progname,gtffilename,funcencrfilename,outfilename = sys.argv
termgenes = defaultdict(list)
with open(gtffilename, 'r') as gtf :
for line in gtf:
linefields = line.strip().split('\t')
term, gene = linefields[8],linefields[0]
termgenes[term].append(gene)
#write output file
with open(funcencrfilename, 'r') as funcencrfile, open(outfilename, 'w') as outfile:
for line in funcencrfile:
term, des = line.strip().split('\t')
outfile.write('%s\t%s%s\n' % term,des,'\t'.join(termgenes[term]))

How to write to a specific line in a text file

I hope I'm not reposting (I did research before hand) but I need a little help.
So I'll explain the problem as best as I can.
I have is a text file, and inside it I have information in this format:
a 10
b 11
c 12
I read this file and convert it to a dictionary with the first column as the key, and the second as the value.
Now I'm trying to do the opposite, I need to be able to write the file back with modified values in the same format, the key separated by a space, then the corresponding value.
Why would I want to do this?
Well, all the values are supposed to be changeable by the user using the program. So when the do decide to change the values, I need them to be written back to the text file.
This is where the problem is, I just don't know how to do it.
How might I go about doing this?
I've got my current code for reading the values here:
T_Dictionary = {}
with open(r"C:\NetSendClient\files\nsed.txt",newline = "") as f:
reader = csv.reader(f, delimiter=" ")
T_Dictionary = dict(reader)

ok,supposing the dictionary is called A and the file is text.txt i would do that:
W=""
for i in A: # for each key in the dictionary
W+="{0} {1}\n".format(i,A[i]) # Append to W a dictionary key , a space , the value corresponding to that key and start a new line
with open("text.txt","w") as O:
O.write(W)
if i understood what you were asking.
however using this method would leave an empty line at the end of the file ,but that can be removed replacing
O.write(W)
with
O.write(W[0:-1])
i hope it helped

Something like this:
def txtf_exp2(xlist):
print("\n", xlist)
t = open("mytxt.txt", "w+")
# combines a list of lists into a list
ylist = []
for i in range(len(xlist)):
newstr = xlist[i][0] + "\n"
ylist.append(newstr)
newstr = str(xlist[i][1]) + "\n"
ylist.append(newstr)
t.writelines(ylist)
t.seek(0)
print(t.read())
t.close()
def txtf_exp3(xlist):
# does the same as the function above but is simpler
print("\n", xlist)
t = open("mytext.txt", "w+")
for i in range(len(xlist)):
t.write(xlist[i][0] + "\n" + str(xlist[i][1]) + "\n")
t.seek(0)
print(t.read())
t.close()
You'll have to make some changes, but it's very similar to what you're trying to do. M