Set operator in python

Python Help
1

Currently, i am unable to save the dictionary data using set operator. can you check whether the syntax is correct.

def get_table_details(conn, ctry, city, cate):
    cur = conn.cursor()
    names = {}
    cur.execute(""" select inputfies from input_tables where a.country= %s and a.client= %s and a.category_code= %s """, (ctry, city, cate))
    for row in cur:
        names[row[0]] = 1
    return names

tablelist = get_table_details(conn, ctry, city, cate)

# Open the tablemeasure.txt file in read mode
required = tablelist.keys()
2

On the face of if…

for row in cur:
        names[row[0]] = 1

… does not look right to me, but as I’ve no idea what row is pulling from cur, I can’t be sure.

What does…

for row in cur:
    print(row)

… look like?

3

You have defined a dictionary not a set.
If you want a set use this


def get_table_details(conn, ctry, city, cate):
    cur = conn.cursor()
    names = set()
    cur.execute(""" select inputfies from input_tables where a.country= %s and a.client= %s and a.category_code= %s """, (ctry, city, cate))
    for row in cur:
        names.add(row[0])
    return names
4

Row is a tuple of the selected fields. In this case a tuple of 1 element.

6

I am trying to compare two files and trying to find the unique lines.

I am looking to get rid of writing the temp file.

# Open the column.txt file in read mode
with open(bin+'columnmlist.txt', 'r') as co1:
    # Read the lines from the columnlist.txt file
    actual = col1.readlines()
col1.close()

actual_set = set(actual)

required = tablelist.keys()

required_set = set(required)


missing = actual_set.difference(required_set)
7

You do not seem to need this so delete the line.

In python3 it is not required to call the keys() method of dictionary.
And sets do not keys to ask for. here are some examples.

d = {'x': 4, 'a': 1}
for key in d:
    print(key)
    print(d[key])

list_of_lists = list(d)

s = set(['x', 'a'])
for value in s:
    print(value)

list_of_values = list(s)
8

Exactly as it says. The purpose of a dictionary is to store some non-duplicate “keys” that can be used to look up a corresponding “value” directly. But a set does not have separate keys and values; it just has elements (similarly to a list or a tuple) that cannot be duplicate. It is also not allowed to index into a set. To see all of its elements, iterate over it: for example by using a for loop, or by converting it to a list or tuple with those constructors.