TypeError：“ datetime.date”类型的参数不可迭代

Question

I am having python script which contains fetching data from MySql DB and then parse that data

below is the way I fetch data from MY SQL db

connection = MySQLdb.connect(host = "192.168.1.50", user = "root", 
password = "root", db = "mydb", port = 32768)
cursor = connection.cursor()
cursor.execute("select * from licenses")
data = cursor.fetchall()

Below is small chunk of output

print(data)

((1,
  'MS SQl',
  'eaf5e1b212e0ad3c4a6172a9e9fd30145dd2d9bf070cc2568fdef384ab63254c',
  datetime.date(2017, 2, 23),
  Decimal('30000.00'),
  '21022018',
  2,
  '',
  1,
  None,
  datetime.datetime(2018, 2, 21, 9, 51, 22),
  datetime.datetime(2018, 2, 21, 11, 26, 17),
  None,
  'Hudson Bay',
  'hudson.bay@ifficeemailid.com',
  None,
  None,
  datetime.date(2018, 2, 24),
  '21022018',
  datetime.date(2018, 2, 25),
  1,
  1,
  0,
  None),
 (2,
  'Palo Alto',
  'eaf5e1b212e0',
  datetime.date(2017, 2, 2),
  Decimal('50000.00'),
  '',
  2,
  '',
  1,
  None,
  datetime.datetime(2018, 2, 21, 10, 5, 16),
  datetime.datetime(2018, 2, 26, 12, 21, 51),
  None,
  'John Snow',
  'john.snow@officeemailid.com',
  None,
  None,
  datetime.date(2018, 2, 22),
  'eaf5e1b212e0',
  datetime.date(2018, 2, 22),
  1,
  1,
  0,
  None))

When I tried to get data from row 17 I can get

for row in data:
    print row[17]
2018-02-24
2018-02-22

However when I tried to add condition it wont work.

for row in data:
    if '2018-02-24' in row[17]:
        print('found')
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-50-a5803fbf5283> in <module>()
      1 for row in data:
----> 2     if '2018-02-28' in row[17]:
      3         print(yes)
      4 

TypeError: argument of type 'datetime.date' is not iterable

My Final Objective is getting date from code like = today = datetime.now().strftime("%Y-%m-%d") On above code '2018-02-24' I have hardcoaded, in actual scenario I and getting that fro 'today' variable and check if that date is available in 'row 17'

but getting error, any way to solve this?

Answer 1

You can use in to search for the date in the entire column, not an individual object:

today = datetime.date.today()
if today in (row[17] for row in data):
    print('found')

There is no need to convert to string if you are comparing date objects. If you have datetime instead of date in the column, you need to do one extra transformation:

today = datetime.date.today()
if today in (row[17].date() for row in data):
    print('found')

The explicit generator can be replaced by either map(itemgetter(17), data) or map(datetime.date, map(itemgetter(17), data)) . The latter is only necessary if you have a datetime , which the error shows you don't:

from operator import itemgetter

today = datetime.date.today()
if today in map(itemgetter(17), data):
    print('found')

Notice that none of these versions has an explicit loop. Since generators are iterable, in will do a similar linear search to your original for loop, but faster. The only real difference, aside from speed, is that these examples will stop looking as soon as a match is found, but your loop does not. You could achieve the same result by putting a break statement in the if .

Answer 2

Try this, hope this helps. Assuming row[17] is date object.

import datetime

now = datetime.datetime.now()
tdy = now.strftime("%Y-%m-%d")

for row in data:
    if tdy == row[17]:
        print('found')