How to iterate through rows in a file which is stored in a variable python

Question

I have a decoded file from an html form stored in a variable:

file_data = file.read().decode('utf-8')
print(file_data)

I want to iterate through the file with a counter that keeps track of the row number so that I can get the row number of when the table begins. These are the two ways I've tried to do it:

Method 1:

counter = 0
for row in file_data:
    if row == 'Date,Unique Id,Tran Type,Cheque Number,Payee,Memo,Amount':
        date_line_no = counter
        break
    counter += 1

Method 2:

for line, row in enumerate(file_data):
    first_column = row[0]
    if first_column == 'Date':
        print(row)
        date_line_no = line

My ideal output would be 7, as that is when the table begins with its columns.

Alexander · Accepted Answer · 2022-07-30 03:08:01Z

1

Use the enumerate function, then search for rows that contain a comma, If it does split it by commas and then continue the way your currently are. You should also use a with statement when reading from files. This avoids having to read the whole file in right away and ensures that it properly closes the file at the end.

for example:

with open(filename) as file:
    for i,row in enumerate(file):
        if ',' in row and row.split(',')[0] == 'Date':
            break
print(i)  # output is the index of the header row.

if you must open the file your way then its still the same, except you also need to split the whole file by \n.

file_data = file.read().decode('utf-8')
print(file_data)


for i, row in enumerate(file_data.split('\n')):
    if ',' in row and row.split(',')[0] == 'Date':
        break
print(i)

edited Jul 30, 2022 at 3:08

answered Jul 30, 2022 at 2:37

Alexander

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3 Comments

Nicholas Coetzee Over a year ago

for some reason the rest of my code after running this doesn't work, and it doesn't even print the value of i. Do you have any idea what could be causing this?

Alexander Over a year ago

@NicholasCoetzee Not without you posting more of your code. If you do decide to post more please copy and paste it instead of posting images

Alexander Over a year ago

@NicholasCoetzee try the bottom example again...there was a bug

Sanju Halder · Accepted Answer · 2022-07-31 08:52:25Z

0

# Opening the file
file = open('your_file_name_or_location') 

# adding a counter for each line
for index, content in enumerate(file):

    var = content.split(',')   # Spliting each line by ','
    if var[0] == 'date':       
        break                  # Getting out of loop if first element is 'date'
print(index + 1)  # Position of header of the table

edited Jul 31, 2022 at 8:52

answered Jul 30, 2022 at 6:33

Sanju Halder

967 bronze badges

1 Comment

Tyler2P Over a year ago

Your answer could be improved by adding more information on what the code does and how it helps the OP.

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