"""
Module for parsing header files.
This module will eventually replace _header.py
"""
import datetime
import re
from typing import List, Tuple
class HeaderSyntaxError(ValueError):
"""Invalid syntax found in a WFDB header file."""
# Record line pattern. Format:
# RECORD_NAME/NUM_SEG NUM_SIG SAMP_FREQ/COUNT_FREQ(BASE_COUNT_VAL) SAMPS_PER_SIG BASE_TIME BASE_DATE
rx_record = re.compile(
r"""
[ \t]* (?P<record_name>[-\w]+)
/?(?P<n_seg>\d*)
[ \t]+ (?P<n_sig>\d+)
[ \t]* (?P<fs>\d*\.?\d*)
/*(?P<counter_freq>-?\d*\.?\d*)
\(?(?P<base_counter>-?\d*\.?\d*)\)?
[ \t]* (?P<sig_len>\d*)
[ \t]* (?P<base_time>\d{,2}:?\d{,2}:?\d{,2}\.?\d{,6})
[ \t]* (?P<base_date>\d{,2}/?\d{,2}/?\d{,4})
""",
re.VERBOSE,
)
# Signal line pattern. Format:
# FILE_NAME FORMATxSAMP_PER_FRAME:SKEW+BYTE_OFFSET ADC_GAIN(BASELINE)/UNITS ADC_RES ADC_ZERO CHECKSUM BLOCK_SIZE DESCRIPTION
rx_signal = re.compile(
r"""
[ \t]* (?P<file_name>~?[-\w]*\.?[\w]*)
[ \t]+ (?P<fmt>\d+)
x?(?P<samps_per_frame>\d*)
:?(?P<skew>\d*)
\+?(?P<byte_offset>\d*)
[ \t]* (?P<adc_gain>-?\d*\.?\d*e?[\+-]?\d*)
\(?(?P<baseline>-?\d*)\)?
/?(?P<units>[\w\^\-\?%\/]*)
[ \t]* (?P<adc_res>\d*)
[ \t]* (?P<adc_zero>-?\d*)
[ \t]* (?P<init_value>-?\d*)
[ \t]* (?P<checksum>-?\d*)
[ \t]* (?P<block_size>\d*)
[ \t]* (?P<sig_name>[\S]?[^\t\n\r\f\v]*)
""",
re.VERBOSE,
)
# Segment line
rx_segment = re.compile(
r"""
[ \t]* (?P<seg_name>[-\w]*~?)
[ \t]+ (?P<seg_len>\d+)
""",
re.VERBOSE,
)
def wfdb_strptime(time_string: str) -> datetime.time:
"""
Given a time string in an acceptable WFDB format, return
a datetime.time object.
Valid formats: SS, MM:SS, HH:MM:SS, all with and without microsec.
Parameters
----------
time_string : str
The time to be converted to a datetime.time object.
Returns
-------
datetime.time object
The time converted from str format.
"""
n_colons = time_string.count(":")
if n_colons == 0:
time_fmt = "%S"
elif n_colons == 1:
time_fmt = "%M:%S"
elif n_colons == 2:
time_fmt = "%H:%M:%S"
if "." in time_string:
time_fmt += ".%f"
return datetime.datetime.strptime(time_string, time_fmt).time()
def parse_header_content(
header_content: str,
) -> Tuple[List[str], List[str]]:
"""
Parse the text of a header file.
Parameters
----------
header_content: str
The string content of the full header file
Returns
-------
header_lines : List[str]
A list of all the non-comment lines
comment_lines : List[str]
A list of all the comment lines
"""
header_lines, comment_lines = [], []
for line in header_content.splitlines():
line = line.strip()
# Comment line
if line.startswith("#"):
comment_lines.append(line)
# Non-empty non-comment line = header line.
elif line:
header_lines.append(line)
return header_lines, comment_lines