expand day name on cal unix command

cal.sh

#!/usr/bin/sh

cal | python3 -c "
import sys
lines = sys.stdin.read().splitlines()

# Replace weekday abbreviations with full names, ensuring consistent spacing
header = lines[1]
header = header.replace('Su', 'Sunday   ').replace('Mo', 'Monday   ').replace('Tu', 'Tuesday  ').replace('We', 'Wednesday').replace('Th', 'Thursday ').replace('Fr', 'Friday   ').replace('Sa', 'Saturday ')

# Print the month/year and the modified header
print(lines[0])
print(header)

# Format and print each line of the calendar
for line in lines[2:]:
    formatted_line = ' '.join(day.ljust(9) if day.isdigit() else day for day in line.split())
    print(formatted_line)
"