# How do you extract the numbers from a text file while also stating the line each appears on? (Python)

## Question:

I need to know how to extract a number from a text file while also having it tell me what line the number is on. But i need it to paste the output to a new text file

Program:

```
fname = input("Enter file name: ")
with open(fname, 'r') as f:
for line in f:
words = line.split()
for i in words:
for letter in i:
if(letter.isdigit()):
print('I found ',letter)
```

Text File:

```
fufge55gf6eh6h6eh6f9hg9hj
vgcg57vgr6vgn66cg4w3vgv78v
gv3c4ghc978c67654cchch
v4bci7r6ec5wgv
```

Output:

```
Enter file name: superpleasework.txt
I found 5
I found 5
I found 6
I found 6
I found 6
I found 6
I found 9
I found 9
I found 5
I found 7
I found 6
I found 6
I found 6
I found 4
I found 3
I found 7
I found 8
I found 3
I found 4
I found 9
...etc
```

I was expecting it to look like this:

```
I found 55 on line 1
I found 6 on line 1
I found 6 on line 1
I found 6 on line 1
I found 6 on line 1
I found 9 on line 1
I found 9 on line 1...etc
```

I need it to tell me the line each number is on (without separating the numbers that are together).

## Answers:

You wrote

```
for line in f:
```

If you wrap that file iterator with

enumerate

your problem becomes simple.

```
for line_num, line in enumerate(f):
...
print('I found ', letter, 'on line number', line_num)
```

You could use the groupby function (form itertools) with the str.isdigit function to separate the lines on the alternating numeric and non-numeric sequences of characters.

To get the line numbers, use enumerate() in your for-loop:

```
from itertools import groupby
for lineNumber,line in enumerate(f,1):
numbers = ("".join(digits) for isNum,digits
in groupby(line,str.isdigit) if isNum)
for number in numbers:
print("I found ",number,"on line",lineNumber)
```

output:

```
I found 55 on line 1
I found 6 on line 1
I found 6 on line 1
I found 6 on line 1
I found 6 on line 1
I found 9 on line 1
I found 9 on line 1
I found 57 on line 2
I found 6 on line 2
I found 66 on line 2
I found 4 on line 2
I found 3 on line 2
I found 78 on line 2
I found 3 on line 3
I found 4 on line 3
I found 978 on line 3
I found 67654 on line 3
I found 4 on line 4
I found 7 on line 4
I found 6 on line 4
I found 5 on line 4
```