How to return line of latest field in text file with Python?

Question

I'm writing a Python script. I need to return lines that contain latest 'timestamp': field from a text file. For example, in the below text file example:

{'uid': 3167, 'user_id': '6', 'timestamp': datetime.datetime(2021, 3, 10, 18, 7, 13), 'status': 1, 'punch': 1}, {'uid': 3168, 'user_id': '198', 'timestamp': datetime.datetime(2021, 3, 10, 18, 10, 42), 'status': 2, 'punch': 1}, {'uid': 3169, 'user_id': '3', 'timestamp': datetime.datetime(2021, 3, 10, 18, 13, 53), 'status': 1, 'punch': 1}, {'uid': 3170, 'user_id': '13', 'timestamp': datetime.datetime(2021, 3, 10, 18, 22, 2), 'status': 1, 'punch': 1}, {'uid': 3171, 'user_id': '9', 'timestamp': datetime.datetime(2021, 3, 10, 18, 22, 43), 'status': 1, 'punch': 1}, {'uid': 3172, 'user_id': '15', 'timestamp': datetime.datetime(2021, 3, 10, 18, 32, 30), 'status': 2, 'punch': 1}, {'uid': 3173, 'user_id': '4', 'timestamp': datetime.datetime(2021, 3, 10, 19, 42, 26), 'status': 1, 'punch': 1}, {'uid': 3174, 'user_id': '1', 'timestamp': datetime.datetime(2021, 3, 10, 19, 42, 34), 'status': 1, 'punch': 1}, {'uid': 3175, 'user_id': '3', 'timestamp': datetime.datetime(2021, 3, 11, 8, 48, 6), 'status': 1, 'punch': 1}, {'uid': 3176, 'user_id': '7', 'timestamp': datetime.datetime(2021, 3, 11, 9, 2, 30), 'status': 2, 'punch': 1}, {'uid': 3177, 'user_id': '5', 'timestamp': datetime.datetime(2021, 3, 11, 9, 12, 40), 'status': 1, 'punch': 1}, {'uid': 3178, 'user_id': '6', 'timestamp': datetime.datetime(2021, 3, 11, 9, 40, 47), 'status': 1, 'punch': 1}, {'uid': 3179, 'user_id': '15', 'timestamp': datetime.datetime(2021, 3, 11, 9, 49, 59), 'status': 2, 'punch': 1},

Return Text File 'today's date 11/3/2021' ex:

{'uid': 3175, 'user_id': '3', 'timestamp': datetime.datetime(2021, 3, 11, 8, 48, 6), 'status': 1, 'punch': 1}, {'uid': 3176, 'user_id': '7', 'timestamp': datetime.datetime(2021, 3, 11, 9, 2, 30), 'status': 2, 'punch': 1}, {'uid': 3177, 'user_id': '5', 'timestamp': datetime.datetime(2021, 3, 11, 9, 12, 40), 'status': 1, 'punch': 1}, {'uid': 3178, 'user_id': '6', 'timestamp': datetime.datetime(2021, 3, 11, 9, 40, 47), 'status': 1, 'punch': 1}, {'uid': 3179, 'user_id': '15', 'timestamp': datetime.datetime(2021, 3, 11, 9, 49, 59), 'status': 2, 'punch': 1},

Reti43 · Accepted Answer · 2021-03-11T10:40:27.090

It seems you're dealing with tabular data and pandas is very natural for that.

import datetime
import pandas as pd

df = pd.DataFrame([{'uid': 3167, 'user_id': '6', 'timestamp': datetime.datetime(2021, 3, 10, 18, 7, 13), 'status': 1, 'punch': 1}, {'uid': 3168, 'user_id': '198', 'timestamp': datetime.datetime(2021, 3, 10, 18, 10, 42), 'status': 2, 'punch': 1}, {'uid': 3169, 'user_id': '3', 'timestamp': datetime.datetime(2021, 3, 10, 18, 13, 53), 'status': 1, 'punch': 1}, {'uid': 3170, 'user_id': '13', 'timestamp': datetime.datetime(2021, 3, 10, 18, 22, 2), 'status': 1, 'punch': 1}, {'uid': 3171, 'user_id': '9', 'timestamp': datetime.datetime(2021, 3, 10, 18, 22, 43), 'status': 1, 'punch': 1}, {'uid': 3172, 'user_id': '15', 'timestamp': datetime.datetime(2021, 3, 10, 18, 32, 30), 'status': 2, 'punch': 1}, {'uid': 3173, 'user_id': '4', 'timestamp': datetime.datetime(2021, 3, 10, 19, 42, 26), 'status': 1, 'punch': 1}, {'uid': 3174, 'user_id': '1', 'timestamp': datetime.datetime(2021, 3, 10, 19, 42, 34), 'status': 1, 'punch': 1}, {'uid': 3175, 'user_id': '3', 'timestamp': datetime.datetime(2021, 3, 11, 8, 48, 6), 'status': 1, 'punch': 1}, {'uid': 3176, 'user_id': '7', 'timestamp': datetime.datetime(2021, 3, 11, 9, 2, 30), 'status': 2, 'punch': 1}, {'uid': 3177, 'user_id': '5', 'timestamp': datetime.datetime(2021, 3, 11, 9, 12, 40), 'status': 1, 'punch': 1}, {'uid': 3178, 'user_id': '6', 'timestamp': datetime.datetime(2021, 3, 11, 9, 40, 47), 'status': 1, 'punch': 1}, {'uid': 3179, 'user_id': '15', 'timestamp': datetime.datetime(2021, 3, 11, 9, 49, 59), 'status': 2, 'punch': 1},])

today = pd.to_datetime('today').normalize()
rows = df[df['timestamp'] >= today]

Which gives

     uid user_id           timestamp  status  punch
8   3175       3 2021-03-11 08:48:06       1      1
9   3176       7 2021-03-11 09:02:30       2      1
10  3177       5 2021-03-11 09:12:40       1      1
11  3178       6 2021-03-11 09:40:47       1      1
12  3179      15 2021-03-11 09:49:59       2      1

If you want the result in a list of dicts, you can then do rows.to_dict('records').

Without pandas it'd be a similar approach of getting today's datetime and iterating over your data to filter them.

lines = [{'uid': 3167, 'user_id': '6', 'timestamp': datetime.datetime(2021, 3, 10, 18, 7, 13), 'status': 1, 'punch': 1}, {'uid': 3168, 'user_id': '198', 'timestamp': datetime.datetime(2021, 3, 10, 18, 10, 42), 'status': 2, 'punch': 1}, {'uid': 3169, 'user_id': '3', 'timestamp': datetime.datetime(2021, 3, 10, 18, 13, 53), 'status': 1, 'punch': 1}, {'uid': 3170, 'user_id': '13', 'timestamp': datetime.datetime(2021, 3, 10, 18, 22, 2), 'status': 1, 'punch': 1}, {'uid': 3171, 'user_id': '9', 'timestamp': datetime.datetime(2021, 3, 10, 18, 22, 43), 'status': 1, 'punch': 1}, {'uid': 3172, 'user_id': '15', 'timestamp': datetime.datetime(2021, 3, 10, 18, 32, 30), 'status': 2, 'punch': 1}, {'uid': 3173, 'user_id': '4', 'timestamp': datetime.datetime(2021, 3, 10, 19, 42, 26), 'status': 1, 'punch': 1}, {'uid': 3174, 'user_id': '1', 'timestamp': datetime.datetime(2021, 3, 10, 19, 42, 34), 'status': 1, 'punch': 1}, {'uid': 3175, 'user_id': '3', 'timestamp': datetime.datetime(2021, 3, 11, 8, 48, 6), 'status': 1, 'punch': 1}, {'uid': 3176, 'user_id': '7', 'timestamp': datetime.datetime(2021, 3, 11, 9, 2, 30), 'status': 2, 'punch': 1}, {'uid': 3177, 'user_id': '5', 'timestamp': datetime.datetime(2021, 3, 11, 9, 12, 40), 'status': 1, 'punch': 1}, {'uid': 3178, 'user_id': '6', 'timestamp': datetime.datetime(2021, 3, 11, 9, 40, 47), 'status': 1, 'punch': 1}, {'uid': 3179, 'user_id': '15', 'timestamp': datetime.datetime(2021, 3, 11, 9, 49, 59), 'status': 2, 'punch': 1},]

today = datetime.date.today()
today = datetime.datetime(today.year, today.month, today.day)
result = [line for line in lines if line['timestamp'] >= today]

I have a question please, can i print end of each line in new line? — Abdullah Md, Mar 11 '21 at 14:59
@AbdullahMd I don't understand the question. Do you want to print each dict in a new line? — Reti43, Mar 11 '21 at 21:15
@AbdullahMd https://stackoverflow.com/questions/13443588/how-can-i-format-a-list-to-print-each-element-on-a-separate-line-in-python — Reti43, Mar 14 '21 at 11:54

How to return line of latest field in text file with Python?

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