Replacing a line in file moves another line to a superior one

Question

I have a py file like the following one:

final_data = ','.join(ordered_data.iloc[0].astype(str).values.tolist())
runtime = boto3.client('runtime.sagemaker')
response = runtime.invoke_endpoint(EndpointName='xgboost-whatever', #Endpoint mark                                           
                                       ContentType='text/csv',
                                       Body=final_data)

What I want is to replace the line with the EndpointName for another line. Taking in account the SO question Search and replace a line in a file in Python I have coded this:

def replace(file_path, subst):
    #Create temp file
    fh, abs_path = mkstemp()
    with fdopen(fh,'w') as new_file:
        with open(file_path) as old_file:
            for line in old_file:
                if re.search('response = runtime.invoke_endpoint(.*?)#Endpoint mark',line):
                    new_file.write(line.replace(line, subst))
                else:
                    new_file.write(line)
    #Remove original file
    remove(file_path)
    #Move new file
    move(abs_path, file_path)


file_path = '/home/whatever'
subst = "        response = runtime.invoke_endpoint(EndpointName='xgboost-otro', #Endpoint mark "

replace(file_path, subst)

However, running the previous code gets me something different that what I was looking for:

final_data = ','.join(ordered_data.iloc[0].astype(str).values.tolist())
runtime = boto3.client('runtime.sagemaker')
response = runtime.invoke_endpoint(EndpointName='xgboost-otro', #Endpoint mark                                                                              ContentType='text/csv',
                                       Body=final_data)

So I lose the ContentType line, which is converted to a comment. If I introduce an \n character at the end of subst it deletes the ContentType line. How could I solve it?

`line.replace(line, subst)` is so cryptic way of saying `subst`. But you need to add a newline. Use `new_file.write("{}\n".format(subst))` instead of `new_file.write(line.replace(line, subst))` — Wiktor Stribiżew, Oct 02 '19 at 10:03
Adding the 'r' has solved the problem. Thanks! Make an answer so that I can accept it (if you want, of course) — Javier Lopez Tomas, Oct 02 '19 at 10:13

Charif DZ · Answer 1 · 2019-10-02T10:18:07.800

1

You forgot the \n at the end of the line:

subst = "        response = runtime.invoke_endpoint(EndpointName='xgboost-otro', #Endpoint mark\n"

and in your replacing logic:

   new_file.write(subst)

edited Oct 02 '19 at 10:18

answered Oct 02 '19 at 10:05

Charif DZ

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It might not be enough since OP syas the ContentType line is removed. – Wiktor Stribiżew Oct 02 '19 at 10:06
thanks for your answer. As I mentioned in my question, if I make this, the whole ContentType line gets deleted – Javier Lopez Tomas Oct 02 '19 at 10:06
It didn't remove it, when I tried it? what do you mean by remove it? you mean the line will not appear at all? – Charif DZ Oct 02 '19 at 10:11
Exactly, that is what I mean – Javier Lopez Tomas Oct 02 '19 at 10:13
but it didn't remove it in my case, and there is no way that it will be remove it? are you sure? – Charif DZ Oct 02 '19 at 10:14
Yes, I am sure. It seems very weird to me as well. I guess it is somehow related to not opening the file in read mode, I don't know – Javier Lopez Tomas Oct 02 '19 at 10:17
the mode is by default a in reading mode so this is not the problem? the error was in using the replace that you didn't need it at all, just write the subst direcly – Charif DZ Oct 02 '19 at 10:19

score 1 · Accepted Answer · answered Oct 02 '19 at 10:15

1

You need to open the file in read mode:

with open(file_path, 'r') as old_file:

Also, line.replace(line, subst) is so cryptic way of saying subst. You need to add a newline at the end of subst anyway or use

new_file.write("{}\n".format(subst))

instead of

new_file.write(line.replace(line, subst))

answered Oct 02 '19 at 10:15

Wiktor Stribiżew

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@CharifDZ It makes a difference though. I can't find the comment on SO that explained it, I will share once I find it. – Wiktor Stribiżew Oct 02 '19 at 10:20

Replacing a line in file moves another line to a superior one

2 Answers2