How to compare elements in lists and check if first list element contains in another list's ele-CodePudding

I have two lists l1 and l2 contains elements like

l1 = ['a','b','c','d']
l2 = ['a is greater', 'f is greater', 'c is greater']

I want to compare elements of l1 and finds if l2 contains in their element or not. The desire output would be

f is greater

Following the code I tried,

for i in l2:
    for j in l2:
    if j not in l1:
        print(i)

but what my observed output is

a is greater
a is greater
f is greater
f is greater
c is greater
c is greater

Please help me out to know what I need to add to get the appropriate output. Thanks.

CodePudding user response：

Use:

l1 = ['a','b','c','d']
l2 = ['a is greater', 'f is greater', 'c is greater']

# iterate over the elements of l2
for i in l2:

    # check if the first letter of e is in l1
    if i[0] not in l1:
        print(i)

Output

f is greater

You don't need to iterate twice over the elements of l2, and to check if if a value (i[0]) is in a collection (l1) use in.

UPDATE

If you want to check a different position just change the index on i, for example, if you wan to check the last position do:

l1 = ['a','b','c','d']
l2 = ['Greater is c', 'Greater is f', 'Greater is d']

# iterate over the elements of l2
for i in l2:

    # check if the first letter of e is in l1
    if i[-1] not in l1:  # note the -1
        print(i)

Output

Greater is f

If you want consider where all words (delimited by spaces) of a sentencer are not present in l1, one approach:

l1 = ['a', 'b', 'c', 'd']
l2 = ['Greater is c', 'Greater is f', 'f is greater', "Hello a cat"]

s1 = set(l1)

# iterate over the elements of l2
for i in l2:

    # check if the first letter of e is in l1
    if s1.isdisjoint(i.split()):
        print(i)

Output

Greater is f
f is greater

If checking for string containment, do:

l1 = ['Book Date:', 'Statement Number:', 'Opening Book Balance:', 'Closing Book Balance:', 'Number Of Debits:',
      'Number of Credits:', 'Total Debits:', 'Total Credits:', 'Report Date:', 'Created by:', 'Modified by:', 'Printed by:']
l2 = ['<p>Book Date: 06-01-21 To 06-30-21</p>', '<p>Statement Number: 126 </p>', '<p>this value need to print</p>']


# iterate over the elements of l2
for i in l2:

    # check if the first letter of e is in l1
    if not any(j in i for j in l1):
        print(i)

Output

<p>this value need to print</p>

CodePudding user response：

Here you go:

ref = ('a','b','c','d')
l2 = ['a is greater', 'f is greater', 'c is greater']
l3 = ['Greater is c', 'Greater is f', 'Greater is d']
l4 = ['...c...', '...f...', '...d...']

[item for item in l2 if not item.startswith(ref)] # 'f is greater'
[item for item in l3 if not item.endswith(ref)]   # 'Greater is f'
[item for item in l4 if not any(letter in item for letter in ref)] # '...f...'