Develop Reference

Why does this error occur when my text files have clearly more than 1 lines?

I'm a beginner in Python. I've checked my text files, and definitely have more than 1 lines, so I don't understand why it gave me the error on
---> 11 Coachid.append(split[1].rstrip())
IndexError: list index out of range

The problem are the lines:
split=line.split(",")
Coachname.append(split[0].rstrip())
Coachid.append(split[1].rstrip())
The first line assumes that line contains at lest one comma so that after method split is called variable split will be a list of at least length two. But if line contains no commas, then split will have length 1 and Coachid.append(split[1].rstrip()) will generate the error you are getting. You need to add some conditional tests of the length of split.
Update
Your code should look like (assuming that the correct action is to append an empty string to the Coachid list if it is missing from the input):
split=line.split(",")
split_length = len(split)
Coachname.append(split[0].rstrip())
# append '' if split_length is less than 2:
Coachid.append('' if split_length < 2 else split[1].rstrip())
etc. for the other fields

If you want to loop over lines of a file, you have to use
for line in f.readlines()
...

Python: Split a string into different elements after a ,

I'm trying to find a way to split a string that I searched for into a few subelements to find information.
My Text has this structure:
INPUT_1_NAME=INPUT_1_NAME,INPUT_1_SDI_ERRCNT=0,INPUT_1_STANDARD=625/25i,INPUT_1_STATE=OK,INPUT_1_TYPE=HD / SD / 3G SDI,INPUT_2_IDENT=2,INPUT_2_NAME=INPUT_2_NAME,INPUT_2_SDI_ERRCNT=0,
My Script so far is:
with open('Test.rtf') as f:
for line in f:
if 'NAME=NEQ1-VIF2601' in line:
I searched in the whole Text file for the information of the device NEQ1-VIF2601. Now i want to find the INPUT_1_SDI_ERRCNT information out of this string for example

Do you mean something like this? This will split every line at a comma and split every resulting element to left (left side of equal-sign) and right (right side of equal -sign)
with open('Test.rtf') as f:
for line in f:
for element in line.split(","):
left, right = element.split("=")[0], element.split("=")[1]

Note:- Please make sure that when you any query it should be understandable for others so that you can get solution very easily and quickly.
Solution for this is. You can split the input string on "," then a new list you will get and then check if "INPUT_1_SDI_ERRCNT is present inside the new list and the fetch the value from this new list.
Solution:-
find_str = 'INPUT_1_SDI_ERRCNT'
for a in l:
k = a.split('=')
if k[0] == find_str:
print(k[1])

Looping a write command to output many different indices from a list separately in Python

Im trying to get an output like:
KPLR003222854-2009131105131
in a text file. The way I am attempting to derive that output is as such:
with open('Processed_Data.txt', 'r') as file_P, open('KIC_list.txt', 'w') as namelist:
nameData = []
for line in file_P:
splt_file_P = line.split()
nameData.append(splt_file_P[0])
for key in nameData:
namelist.write('\n' 'KPLR00' + "".join(str(w) for w in nameData) + '-2009131105131')
However I am having an issue in that the numbers in the nameData array are all appearing at once in the specified output, instead of using on ID cleanly as shown above the output is something like this:
KPLR00322285472138721382172198371823798123781923781237819237894676472634973256279234987-2009131105131
So my question is how do I loop the write command in a way that will allow me to get each separate ID (each has a specific index value, but there are over 150) to be properly outputted.
EDIT:
Also, some of the ID's in the list are not the same length, so I wanted to add 0's to the front of the 'key' to make them all equal 9 digits. I cheated this by adding the 0's into the KPLR in quotes but not all of the ID's need just two 0's. The question is, could I add 0's between KPLR and the key in any way to match the 9-digit format?

Your code looks like it's working as one would expect: "".join(str(w) for w in nameData) makes a string composed of the concatenation of every item in nameData.
Chances are you want;
for key in nameData:
namelist.write('\n' 'KPLR00' + key + '-2009131105131')
Or even better:
for key in nameData:
namelist.write('\nKPLR%09i-2009131105131'%int(key)) #no string concatenation
String concatenation tends to be slower, and if you're not only operating on strings, will involve explicit calls to str. Here's a pair of ideone snippets showing the difference: http://ideone.com/RR5RnL and http://ideone.com/VH2gzx
Also, the above form with the format string '%09i' will pad with 0s to make the number up to 9 digits. Because the format is '%i', I've added an explicit conversion to int. See here for full details: http://docs.python.org/2/library/stdtypes.html#string-formatting-operations
Finally, here's a single line version (excepting the with statement, which you should of course keep):
namelist.write("\n".join("KPLR%09i-2009131105131"%int(line.split()[0]) for line in file_P))

You can change this:
"".join(str(w) for w in nameData)
to this:
",".join(str(w) for w in nameData)
Basically, the "," will comma delimit the elements in your nameData list. If you use "", then there will be nothing to separate the elements, so they appear all at once. You can change the delimiter to suit your needs.

Just for kicks:
with open('Processed_Data.txt', 'r') as file_P, open('KIC_list.txt', 'w') as namelist:
nameData = [line.split()[0] for line in file_P]
namelist.write("\n".join("KPLR00" + str(key) + '-2009131105131' for key in nameData))
I think that will work, but I haven't tested it. You can make it even smaller/uglier by not using nameData at all, and just use that list comprehension right in its place.

How would you find text in a string in python and then look for a number after it?

I have a log file and at the end of each line in the file there is this string:
Line:# where # is the line number.
I am trying to get the # and compare it to the previous line's number. what would be the best way to do that in python?

I would probably use str.split because it seems easy:
with open('logfile.log') as fin:
numbers = [ int(line.split(':')[-1]) for line in fin ]
Now you can use zip to compare one number with the next one:
for num1,num2 in zip(numbers,numbers[1:]):
compare(num1,num2) #do comparison here.
Of course, this isn't lazy (you store every line number in the file at once when you really only need 2 at a time), so it might take up a lot of memory if your files are HUGE. It wouldn't be hard to make it lazy though:
def elem_with_next(iterable):
ii = iter(iterable)
prev = next(ii)
for here in ii:
yield prev,here
prev = here
with open('logfile.log') as fin:
numbers = ( int(line.split(':')[-1]) for line in fin )
for num1,num2 in elem_with_next(numbers):
compare(num1,num2)

I'm assuming that you don't have something convenient to split a string on, meaning a regular expression might make more sense. That is, if the lines in your log file are structured like:
date: 1-15-2013, error: mildly_annoying, line: 121
date: 1-16-2013, error: err_something_bad, line: 123
Then you won't be able to use line.split('#') as mgilson as suggested, although if there is always a colon, line.split(':') might work. In any case, a regular expression solution would look like:
import re
numbers = []
for line in log:
digit_match = re.search("(\d+)$", line)
if digit_match is not None:
numbers.append(int(digit_match.group(1)))
Here the expression "(\d+)$" is matching some number of digits and then the end of the line. We extract the digits with the group(1) method on the returned match object and then add them to our list of line numbers.
If you're not confident that the "Line: #" will always come at the end of the log, you could replace the regular expression used above with something akin to "Line:\s*(\d+)" which checks for the string "Line:" then some (or no) whitespace, and then any number of digits.

Get a value from a string in python

Program Details:
I am writing a program for python that will need to look through a text file for the line:
Found mode 1 of 12: EV= 1.5185449E+04, f= 19.612545, T= 0.050988.
Problem:
Then after the program has found that line, it will then store the line into an array and get the value 19.612545, from f = 19.612545.
Question:
I so far have been able to store the line into an array after I have found it. However I am having trouble as to what to use after I have stored the string to search through the string, and then extract the information from variable f. Does anyone have any suggestions or tips on how to possibly accomplish this?

Depending upon how you want to go at it, CosmicComputer is right to refer you to Regular Expressions. If your syntax is this simple, you could always do something like:
line = 'Found mode 1 of 12: EV= 1.5185449E+04, f= 19.612545, T= 0.050988.'
splitByComma=line.split(',')
fValue = splitByComma[1].replace('f= ', '').strip()
print(fValue)
Results in 19.612545 being printed (still a string though).
Split your line by commas, grab the 2nd chunk, and break out the f value. Error checking and conversions left up to you!

Using regular expressions here is maddness. Just use string.find as follows: (where string is the name of the variable the holds your string)
index = string.find('f=')
index = index + 2 //skip over = and space
string = string[index:] //cuts things that you don't need
string = string.split(',') //splits the remaining string delimited by comma
your_value = string[0] //extracts the first field
I know its ugly, but its nothing compared with RE.