How to extract the elements only latest timestamp from json irrespective of case sensitive-CodePudding

I have list of dictionary below

rec=[{
    'Name': 'aRe',
    'Email': '[email protected]',
    'timestamp': '2021-11-29T04:33:28.138522Z'
  },
  {
    'Name': 'Umar',
    'Email': '[email protected]',
    'timestamp': '2021-11-28T04:33:28.138522Z'
  },
  
  {
    'Name': 'Are',
    'Email': '[email protected]',
    'timestamp': '2021-11-27T04:33:28.138522Z'
  },
  
  {
    'Name': 'arE',
    'Email': '[email protected]',
    'timestamp': '2021-11-28T06:59:58.975864Z'
  },
    {
    'Name': 'umaR',
    'Email': '[email protected]',
    'timestamp': '2021-11-29T04:33:28.138522Z'
  },
  {
    'Name': 'Sc',
    'Email': '[email protected]',
    'timestamp': '2022-02-01T15:02:12.301701Z'
  }
]

if duplicate id is present then extract the dict with latest timestamp

Expected out

[{'Name': 'umaR',
  'Email': '[email protected]',
  'timestamp': '2021-11-29T04:33:28.138522Z'},
 {'Name': 'aRe',
  'Email': '[email protected]',
  'timestamp': '2021-11-29T04:33:28.138522Z'},
 {'Name': 'Sc',
  'Email': '[email protected]',
  'timestamp': '2022-02-01T15:02:12.301701Z'}]

Code is below

from itertools import groupby
filtered_recs = []
for key, group_iter in groupby(recs, lambda rec: rec['Name'].lower()):
    recent_rec = max(group_iter, key = lambda rec: rec['timestamp'])
    filtered_recs.append(recent_rec)
filtered_recs

My code is working fine if all the 'Name' in same case. Like name are like, 'are', 'umar', 'sc' not for irregular case letters

CodePudding user response：

Sort first the recs:

from itertools import groupby

filtered_recs = []

recs = sorted(recs, key=lambda rec: rec["Name"].lower())  # <-- sort before groupby

for key, group_iter in groupby(recs, lambda rec: rec["Name"].lower()):
    recent_rec = max(group_iter, key=lambda rec: rec["timestamp"])
    filtered_recs.append(recent_rec)

print(filtered_recs)

Prints:

[
    {
        "Name": "aRe",
        "Email": "[email protected]",
        "timestamp": "2021-11-29T04:33:28.138522Z",
    },
    {
        "Name": "Sc",
        "Email": "[email protected]",
        "timestamp": "2022-02-01T15:02:12.301701Z",
    },
    {
        "Name": "umaR",
        "Email": "[email protected]",
        "timestamp": "2021-11-29T04:33:28.138522Z",
    },
]

EDIT: Version without sort:

filtered_recs = {}
for r in recs:
    filtered_recs.setdefault(r["Name"].lower(), []).append(r)

for k, v in filtered_recs.items():
    filtered_recs[k] = max(v, key=lambda rec: rec["timestamp"])

print(list(filtered_recs.values()))

Prints:

[
    {
        "Name": "aRe",
        "Email": "[email protected]",
        "timestamp": "2021-11-29T04:33:28.138522Z",
    },
    {
        "Name": "umaR",
        "Email": "[email protected]",
        "timestamp": "2021-11-29T04:33:28.138522Z",
    },
    {
        "Name": "Sc",
        "Email": "[email protected]",
        "timestamp": "2022-02-01T15:02:12.301701Z",
    },
]