how do i find the index of all occurrences of certain string and store it into list

Question

I have a list/array called position[] and it is used to store the position line number of the string by using find(). The string is the abc.py which is a python file(I will include the abc.py below).

Question: how do find the string position of all def.

Objective: capture the line number of the first def and the second def and third etc and stored it in position[]

abc.py:

 #!C:\Python\Python39\python.exe
    # print ('Content-type: text/html\n\n')

def hello_step0():
    create()
    login()

def hello2_step1():
    delete()

def hello2_step2():
    delete()

What i did to find the first occurrence of def

position = [] 
with open("abc.py","r") as file:
    line = file.readlines()
    line = str(line)
    print(line.strip().find("def")) # output 102
    position.append(line.strip().find("def"))

I think you meant ```line number``` and not ```index``` of ```def``` ? — Ram, Jul 04 '21 at 09:59
yes i mean line number i will edit the word. thanks for the input. — Gerald, Jul 04 '21 at 10:01
Does this answer your question? [Get Line Number of certain phrase in file Python](https://stackoverflow.com/questions/3961265/get-line-number-of-certain-phrase-in-file-python) — Tomerikoo, Jul 04 '21 at 13:00

score 1 · Accepted Answer · edited Jul 04 '21 at 12:59

1

Try str.startswith:

position = [] 

with open("abc.py") as f:
    for index, line in enumerate(f.readlines()):
        if line.strip().startswith('def'):
            position.append(index)

print(position) #[3, 7, 10] --> line starts with 0

# 0 --> #!C:\Python\Python39\python.exe
# 1--->    # print ('Content-type: text/html\n\n')
# 2-->
# 3-->def hello_step0():
#     create()

To start with 1, just replace:

for index, line in enumerate(f.readlines(), 1):

edited Jul 04 '21 at 12:59

Tomerikoo

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answered Jul 04 '21 at 10:03

Epsi95

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You can just pass `f` to `enumerate`. No need to create a list of `f.readlines()` – Tomerikoo Jul 04 '21 at 12:57

score 1 · Answer 2 · answered Jul 04 '21 at 10:07

The Below code will give append line numbers of lines that starts with def to position list.

position = []
with open('abc.py', 'r') as f:
    for i, val in enumerate(f.readlines()):
        if val.startswith('def'):
            position.append(i)

Output:

position = [3,7,10]

how do i find the index of all occurrences of certain string and store it into list

2 Answers2