How to get an index value based on a string available on that index?-CodePudding

For a given text file (sample.txt), I would like to get index value based on a string that is present on that line (index).

An example file contains following text (sample.txt):

line 1: open a file.

line 2: Read a file and store it in a variable.

line 3: check condition using ‘in’ operator for string present in the file or not.

line 4: If the condition true print the index in which the string is found.

line 5: Close a file.

if my target string is 'variable'. The output I would like to have is: 2

CodePudding user response：

This should do:

def indicesOfQueryOnFile(query, file):
    with open(file, 'r') as f:
        cleanLines = [line for line in f.readlines() if len(line.strip()) > 0]
        indices = [i   1 for i, line in enumerate(cleanLines) if query in line]
    
    return indices

For the text file:

line 1: open a file.

line 2: Read a file and store it in a variable.

line 3: check condition using ‘in’ operator for string present in the file or not.

line 4: If the condition true print the index in which the string is found.

line 5: Close a file.

another line with variable

It would output:

indicesOfQueryOnFile('variable', 'test.txt')
# [2, 6]

CodePudding user response：

If I am understanding correctly, something like this might be what you are looking for.

def FindLineIndexOfFile(file, text):
    file = open(file, "r")
    line_count = 0
    for lines in file.readlines():
        line_count  = 1
        line_index = lines.strip()
        if line_index == text:
            file.close()
            return line_count


index = FindLineIndexOfFile("sample.txt", "hello world")

print(index)