Python regex extracting floatin values

Question

I have data that has strings with floating numbers like

"['0.0'" and '82.00.0' and '82.0\n'

and I only want to extract floating points till two/one decimal points like so-

"['0.0'" and '82.00.0' and '82.0\n' to 0.0, 82.0, 82.0

The data structure is a big quoted CSV like:

"0.0, 82.00.0,...., 82.0\n"

I'm iterating through these to store them to the temp

tempprices.split(',') temp =[] for n in range(l, len(tempprices)-1): temp.append(map(ast.literal_eval,re.findall(r'(?<!\S)[+-]?\d+\.\d{1,2}(?!\.*\d)',tempprices[n])))

where l is some index value.

I want to append these to temp like so [0.0, 82.0, 82.0]

How to achieve that?

I think [`re.findall(r"[+-]? *(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][+-]?\d+)?", s)`](http://stackoverflow.com/a/385597/3832970) will do. Just adjust the quantifiers. — Wiktor Stribiżew, Jun 13 '16 at 08:37
Tried this, did not work- `float(re.sub(r'[^0-9.[0-9][0-9]?]', '', price[n]))` — Sushant, Jun 13 '16 at 08:40
Try `re.findall(r"(?<!\S)[+-]?\d+\.\d{1,2}(?!\.*\d)", s)`. Or `import ast`, and then `map(ast.literal_eval,re.findall(r'(?<!\S)[+-]?\d+\.\d{1,2}(?!\.*\d)',s)) ` — Wiktor Stribiżew, Jun 13 '16 at 08:47
When I use `float(re.findall(r"(?<!\S)[+-]?\d+\.\d{1,2}(?!\.*\d)", s))` I get this 'float() argument must be a string or a number, not 'list'' — Sushant, Jun 13 '16 at 09:12
You can't cast a list to a float type. Try using `ast` as I indicated in the comment above. — Wiktor Stribiżew, Jun 13 '16 at 09:17
Ok, what do you expect to obtain? Please add that to the question together with your attempt posted as a comment. Also, here is a sample Python demo: https://ideone.com/lKfz10. — Wiktor Stribiżew, Jun 13 '16 at 10:06
Updated the question, I hope you understand what I want to achieve. Thank you for your time though :) — Sushant, Jun 13 '16 at 10:19
No, that won't work like this: post the relevant code for us in your question body to be able to help you properly. Also, regarding *I split the line with ","s*: why not use a CSV parser? — Wiktor Stribiżew, Jun 13 '16 at 10:21

Wiktor Stribiżew · Accepted Answer · 2016-06-13T12:22:26.527

1

There are several issues:

You did not assign the split chunks to a variable (see tempprices.split(','))
You actually have to extract 1 value, so the re.sub can work, but a re.search is safer

You may use the following fix:

import re

tempprices = "0.0, 82.00.0,...., 82.0\n"
cells = tempprices.split(',')
temp =[]
for t in cells:
    mObj = re.search(r'-?\d+\.\d{1,2}', t)
    if mObj:
        temp.append(float(mObj.group()))
print(temp)

See the IDEONE demo

If you can have multiple float values inside each cell, you will have to use ast.literal_eval with re.findall:

for t in cells:
    temp.extend(map(ast.literal_eval, re.findall(r'-?\d+\.\d{1,2}', t)))
         ^^^^^^ ^^^^^^^^^^^^^^^^^^^^

See another IDEONE demo

edited Jun 13 '16 at 12:22

answered Jun 13 '16 at 11:35

Wiktor Stribiżew

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Thank you so much for your time. This finally worked, and I had split the values, just stored them in the same variable. But thanks :) – Sushant Jun 13 '16 at 12:52
Glad it worked for you. Please also consider upvoting if my answer proved helpful to you (see [How to upvote on Stack Overflow?](http://meta.stackexchange.com/questions/173399/how-to-upvote-on-stack-overflow)). – Wiktor Stribiżew Jun 13 '16 at 13:25

Gal Dreiman · Answer 2 · 2016-06-13T09:23:45.093

0

Try this:

import re

s = '82.00\n    1.3000   9.1'
result = re.findall(r'\d+\.\d{1,2}', s)
print result

Output: ['82.00', '1.30', '9.1']

edited Jun 13 '16 at 09:23

answered Jun 13 '16 at 09:19

Gal Dreiman

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Yes, and `r'\d+.\d{1,2}'` will also grab `1-11` and `1:11` – Wiktor Stribiżew Jun 13 '16 at 09:22

Python regex extracting floatin values

2 Answers2