"""Class to store a block of code and a method to write it to a file

__var_re = re.compile(r"[{][ ]*([A-Za-z][A-Za-z0-9_]*)[ ]*[}]")

__fmt_msg = ('Each element of <code_list> must contain exactly two '

'items, a code string and a relative indent')

def __init__(self, code_list):

"""Initialize object with a list of statements.

self.__code_block = code_list

self.__write_vars = list()

for line in self.__code_block:

if len(line) != 2:

raise ParseInternalError(CodeBlock.__fmt_msg.format(code_list))

# end if

stmt = line[0]

if not isinstance(stmt, str):

raise ParseInternalError(CodeBlock.__fmt_msg.format(code_list))

# end if

if not isinstance(line[1], int):

raise ParseInternalError(CodeBlock.__fmt_msg.format(code_list))

# end if

beg = 0

end = len(stmt)

while beg < end:

# Ignore double curly braces

open_double_curly = stmt.find('{{', beg)

close_double_curly = stmt.find('}}',

max(open_double_curly, beg))

if 0 <= open_double_curly < close_double_curly:

beg = close_double_curly + 2

else:

match = CodeBlock.__var_re.search(stmt[beg:])

if match:

self.__write_vars.append(match.group(1))

beg = stmt.index('}', beg) + 1

else:

beg = end + 1

# end if

# end if

# end while

# end for

def write(self, outfile, indent_level, var_dict):

"""Write this object's code block to <outfile> using <indent_level>

for line in self.__code_block:

stmt = line[0]

if indent_level >= 0:

indent = indent_level + line[1]

else:

indent = 0

# end if

# Check that <var_dict> contains all required items

errmsg = ''

sep = ''

for var in self.__write_vars:

if var not in var_dict:

errmsg += "'{}' missing from <var_dict>".format(sep, var)

sep = '\n'

# end if

# end for

if errmsg:

raise ParseInternalError(errmsg)

# end if

outfile.write(stmt.format(**var_dict), indent)