Simple string operation:

mywords = ("xxx", "yyy", "zzz")
all(x in mystring for x in mywords)

If word boundaries are relevant (i. e. you want to match zzz but not Ozzzy):

import re
all(re.search(r"\b" + re.escape(word) + r"\b", mystring) for word in mywords)

Use lookaheads. ^(?=.*foo|.*bar|.*Python)(?=.*me|.*you|.*we)

Add \b around the words (e.g. \bfoo\b) if you want them as isolated words, otherwise you get matches like fool)

https://regex101.com/r/dnqSjr/1

Yes, I believe this is possible.

To get you started, this is how I would break down the problem.

Calculate the root by finding the longest possible string that matches the start of all of the declined values:

>>> root = ''
>>> for c in hablar['yo']:
...     if all(v.startswith(root + c) for v in hablar.itervalues()):
...         root += c
...     else:
...        break
... 
>>> root
'habl'

Whatever's left of the words makes a list of endings.

>>> endings = [v[len(root):] for v in hablar.itervalues()]
>>> print endings
['abas', 'aba', 'abais', 'aba', '\xc3\xa1bamos', 'aban', 'abas']

You may then want to weed out the duplicates:

>>> unique_endings = set(endings)
>>> print unique_endings
set(['abas', 'abais', '\xc3\xa1bamos', 'aban', 'aba'])

Then join these endings together with pipes:

>>> conjoined_endings = '|'.join(unique_endings)
>>> print conjoined_endings
abas|abais|ábamos|aban|aba

Forming the regular expression is a simple matter combining the root and the conjoined_endings string in parentheses:

>>> final_regex = '{}({})'.format(root, conjoined_endings)
>>> print final_regex
habl(abas|abais|ábamos|aban|aba)

Join the list on the pipe character |, which represents different options in regex.

string_lst = ['fun', 'dum', 'sun', 'gum']
x="I love to have fun."

print re.findall(r"(?=("+'|'.join(string_lst)+r"))", x)

Output: ['fun']

You cannot use match as it will match from start. Using search you will get only the first match. So use findall instead.

Also use lookahead if you have overlapping matches not starting at the same point.

>>> import re
>>> myre = re.compile(r"\w{4,}")
>>> myre.findall('Lorem, ipsum! dolor sit? amet...')
['Lorem', 'ipsum', 'dolor', 'amet']

Take note that in Python 3, where all strings are Unicode, this will also find words that use non-ASCII letters:

>>> import re
>>> myre = re.compile(r"\w{4,}")
>>> myre.findall('Lorem, ipsum! dolör sit? amet...')
['Lorem', 'ipsum', 'dolör', 'amet']

In Python 2, you'd have to use

>>> myre = re.compile(r"\w{4,}", re.UNICODE)
>>> myre.findall(u'Lorem, ipsum! dolör sit? amet...')
[u'Lorem', u'ipsum', u'dol\xf6r', u'amet']

You've got a few problems there.

First, matches are case-sensitive unless you use the IGNORECASE/I flag to ignore case. So, 'AND' doesn't match 'and'.

Also, unless you use the VERBOSE/X flag, those spaces are part of the pattern. So, you're checking for 'AND ', not 'AND'. If you wanted that, you probably wanted spaces on each side, not just those sides (otherwise, 'band leader' is going to match…), and really, you probably wanted \b, not a space (otherwise a sentence starting with 'And another thing' isn't going to match).

Finally, if you think you need .* before and after your pattern and $ and ^ around it, there's a good chance you wanted to use search, findall, or finditer, rather than match.

So:

>>> s = "These are oranges and apples and pears, but not pinapples or .."
>>> r = re.compile(r'\bAND\b | \bOR\b | \bNOT\b', flags=re.I | re.X)
>>> r.findall(s)
['and', 'and', 'not', 'or']

Debuggex Demo

Use word boundary \b

import re

shop="hello seattle what have you got"
regex = r'\b\w+\b'
list1=re.findall(regex,shop)
print list1

OP : ['hello', 'seattle', 'what', 'have', 'you', 'got']

or simply \w+ is enough

import re

shop="hello seattle what have you got"
regex = r'\w+'
list1=re.findall(regex,shop)
print list1

OP : ['hello', 'seattle', 'what', 'have', 'you', 'got']

You need to turn your fruit list into the string apple|banana|peach|plum|pineapple|kiwi so that it is a valid regex. The following should do this for you:

fruit_list = ['apple', 'banana', 'peach', 'plum', 'pineapple', 'kiwi']
fruit = re.compile('|'.join(fruit_list))

As ridgerunner pointed out in comments, you will probably want to add word boundaries to the regex, otherwise the regex will match on words like plump since they have a fruit as a substring.

fruit = re.compile(r'\b(?:%s)\b' % '|'.join(fruit_list))

Lastly, if the strings in fruit_list could contain special characters, you will probably want to use re.escape.

'|'.join(map(re.escape, fruit_list))