passing a variable form a loop to a conditional statement

Question

I have got this function in my program.

def time(transcriptionFile) :
    ''' This function changes the time values in secs from the transcription file and keeps a list of start time and duration for each phoneme.'''
    with open("transcriptions.txt", "r") as tFile :
        timeList = []
        parameterList = []
        frame = 0.04
        lines = 0
        for line in tFile :
            lines += 1
            for i in range(lines) : 
                i = i * frame
            timeList.append(i)
            li = line.split()
            if li :
                start_time = (int(li[0]) / 10000000.)
                end_time = (int(li[1]) / 10000000.) 
                duration = ((int(li[1]) -int(li[0]))/10000000.)

                poly = poly_coeff(start_time, end_time, i)
                Newton(poly, parameterList)

I want to use i as an argument in poly_coeff. The number of times this function is called is the number of lines in the file. And i is increasing with each line. So when the function is called for the first time the first i value should should be passed as argument then second time the second i value should be passed and so on.

I have certainly done it wrong here I can see but can't figure out how to do it in a right way. Also I guess too much is going on inside a single function. Is it better to split it? But everything is to do with opening the same file.

highBandWidth · Accepted Answer · 2011-08-11 18:40:00Z

1

If you want the line number then you should do

poly = poly_coeff(start_time, end_time, lines)

If you want to use line number * frame then do

poly = poly_coeff(start_time, end_time, lines * frame)

I dont know what you are trying to do with

for i in range(lines) : 
    i = i * frame

answered Aug 11, 2011 at 18:40

highBandWidth

17.4k23 gold badges87 silver badges132 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

zingy Over a year ago

yes, I could have done this. I should have a list of lines * frame so I had used the for loop. Thanks

AlG · Accepted Answer · 2011-08-11 18:37:14Z

0

i is only in scope within the for loop. Add a declaration before it so you have access to it later.

<snip>
for line in tFile :
            lines += 1
            i = 0
            for i in range(lines) : 
                i = i * frame
<snip>

... and yes, I vote for more functional programming; break it out a bit to make it more readable.

answered Aug 11, 2011 at 18:37

AlG

15.3k4 gold badges43 silver badges54 bronze badges

2 Comments

Andrew Clark Over a year ago

This is actually incorrect, loops do not create a new scope and any names created in the loop are usable after.

AlG Over a year ago

@F.J I thought so too, until I tried a cut down version of his code and it failed with a variable uninitialized error.

Andrew Clark · Accepted Answer · 2011-08-11 18:41:28Z

0

edit: It looks like you might actually have an indentation error, did you intend to have everything starting with timelist.append(i) inside of the loop with i? That would make more sense.

        ...
        for i in range(lines): 
            i = i * frame
            timeList.append(i)
            li = line.split()
            if li :
                start_time = (int(li[0]) / 10000000.)
                end_time = (int(li[1]) / 10000000.) 
                duration = ((int(li[1]) -int(li[0]))/10000000.)

                poly = poly_coeff(start_time, end_time, i)
                Newton(poly, parameterList)

If the indentation is correct, then I don't think that for loop with i is doing what you think it is, here is an example of what is going on:

>>> for i in range(3):
...   print "before", i
...   i = i * 0.04
...   print "after", i
... 
before 0
after 0.0
before 1
after 0.04
before 2
after 0.08
>>> print i
0.08

So basically, after the loop i is equivalent to (lines-1)*frame. You modify i during each iteration of the loop but it is set back to the next number in the range at the beginning of each iteration.

answered Aug 11, 2011 at 18:41

Andrew Clark

210k36 gold badges285 silver badges310 bronze badges

1 Comment

zingy Over a year ago

I need to make a list of increasing i values as well therefore I used it and it was giving me the proper values. Thanks

Collectives™ on Stack Overflow

passing a variable form a loop to a conditional statement

3 Answers 3

1 Comment

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related