You can do something like this using this kind of pattern:
Using Python3:
import re
data = "Date: Tue, 13 Nov 2001 08:41:49 -0800 (PST)"
final = re.findall(r"Date: (\w+), ([0-9]+) (\w+) ([0-9]+)", data)
print("{0}, {1}".format(final[0][0], " ".join(final[0][1:])))
print(" ".join(final[0][1:]))
Using Python2:
import re
data = "Date: Tue, 13 Nov 2001 08:41:49 -0800 (PST)"
final = re.findall(r"Date: (\w+), ([0-9]+) (\w+) ([0-9]+)", data)
print "%s, %s" % (final[0][0], " ".join(final[0][1:]))
print " ".join(final[0][1:])
Output:
Tue, 13 Nov 2001
13 Nov 2001
Edit:
A quick answer to the new update of your question, you can do something like this:
import re
email = '''Date: Tue, 13 Nov 2001 08:41:49 -0800 (PST)
Sent: Thursday, November 08, 2001 10:25 AM'''
data = email.split("\n")
pattern = r"(\w+: \w+, [0-9]+ \w+ [0-9]+)|(\w+: \w+, \w+ [0-9]+, [0-9]+)"
final = []
for k in data:
final += re.findall(pattern, k)
final = [j.split(":") for k in final for j in k if j != '']
# Python3
print(final)
# Python2
# print final
Output:
[['Date', ' Tue, 13 Nov 2001'], ['Sent', ' Thursday, November 08, 2001']]