In Python, how can I check that a string does not contain any string from a list?

Question

For example, where:

list = [admin, add, swear]
st = 'siteadmin'

st contains string admin from list.

• How can I perform this check?
• How can I be informed which string from list was found, and if possible where (from start to finish in order to highlight the offending string)?

This would be useful for a blacklist.

Answer 1

list = ['admin', 'add', 'swear']
st = 'siteadmin'
if any([x in st for x in list]):print "found"
else: print "not found"

You can use any built-in function to check if any string in the list appeared in the target string

Answer 2

You can do this by using list-comprehessions

ls = [item for item in lst if item in st]

UPD: You wanted also to know position :

ls = [(item,st.find(item)) for item in lst if st.find(item)!=-1]

Result : [('admin', 4)

You can find more information about List Comprehensions on this page

Answer 3

I am assuming the list is very large. So in this program, I am keeping the matched items in a list.

#declaring a list for storing the matched items
matched_items = []
#This loop will iterate over the list
for item in list:
    #This will check for the substring match
    if item in st:
        matched_items.append(item)
#You can use this list for the further logic
#I am just printing here 
print "===Matched items==="
for item in matched_items:
    print item