in functions/source/GitPullS3/ipaddress.py [0:0]
def _compress_hextets(cls, hextets):
"""Compresses a list of hextets.
Compresses a list of strings, replacing the longest continuous
sequence of "0" in the list with "" and adding empty strings at
the beginning or at the end of the string such that subsequently
calling ":".join(hextets) will produce the compressed version of
the IPv6 address.
Args:
hextets: A list of strings, the hextets to compress.
Returns:
A list of strings.
"""
best_doublecolon_start = -1
best_doublecolon_len = 0
doublecolon_start = -1
doublecolon_len = 0
for index, hextet in enumerate(hextets):
if hextet == '0':
doublecolon_len += 1
if doublecolon_start == -1:
# Start of a sequence of zeros.
doublecolon_start = index
if doublecolon_len > best_doublecolon_len:
# This is the longest sequence of zeros so far.
best_doublecolon_len = doublecolon_len
best_doublecolon_start = doublecolon_start
else:
doublecolon_len = 0
doublecolon_start = -1
if best_doublecolon_len > 1:
best_doublecolon_end = (best_doublecolon_start +
best_doublecolon_len)
# For zeros at the end of the address.
if best_doublecolon_end == len(hextets):
hextets += ['']
hextets[best_doublecolon_start:best_doublecolon_end] = ['']
# For zeros at the beginning of the address.
if best_doublecolon_start == 0:
hextets = [''] + hextets
return hextets