# coding=utf8
# the above tag defines encoding for this document and is for Python 2.x compatibility
import re
regex = r"@(\"[\w\s]+\")|(?!@(\w+)@(\w+))@(\w+)"
test_str = ("There is @key1 apples on the table. \n"
"There is @\"key1\" apples on the table. \n"
"There is @key 4 apples on the table.\n"
"There is @\"key 4\" apples on the table.\n\n"
"There is @key@key2 apples on the table.\n"
"There is @key3 apples on the table. (second step)\n\n"
"There is @\"key @\"key3\"\" apples on the table.\n"
"There is @\"key 4\" apples on the table. (second step)\n\n"
"There is @\"key @key3\" apples on the table.\n"
"There is @\"key 4\" apples on the table. (second step)\n\n"
"There is @\"key @key3 \" apples on the table.\n"
"There is @\"key 4 \" apples on the table. (second step)\n\n"
"There is @\"key @\"key3@key7\"\" apples on the table.\n"
"There is @\"key @\"key32\"\" apples on the table. (second step)\n"
"There is @\"key 21\" apples on the table. (3rd step)\n\n"
"There is @key@key2@key3@key4 apples on the table.\n"
"There is @key@key2@key35 apples on the table. (second step)\n"
"There is @key@key26 apples on the table. (3rd step)\n"
"There is @key7 apples on the table. (4th step)\n")
matches = re.finditer(regex, test_str)
for matchNum, match in enumerate(matches, start=1):
print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group()))
for groupNum in range(0, len(match.groups())):
groupNum = groupNum + 1
print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum)))
# Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Python, please visit: https://docs.python.org/3/library/re.html