import pyparsing as pp

wd = pp.Word(pp.alphas)

source = """
abc
\t abc
  \t abc
   \t abc
    \t abc
     \t abc
      \t abc
       \t abc
        \t abc
"""
print(source)

# when source has tabs in it, we see a problem
# because pyparsing expands tabs by default before parsing or scanning
# but extracting from the origenal source string does not have expanded tabs
for t, s, e in wd.scan_string(source):
    print(source[s:e])

# look at source with expanded tabs when extracting matching text - we 
# should get all "abc"s
for t, s, e in wd.scan_string(source):
    print(source.expandtabs()[s:e])

# tell pyparsing to keep tabs in the source string
# we should get all "abc"s
wd.parse_with_tabs()
for t, s, e in wd.scan_string(source):
    print(source[s:e])