How do I check if a string coming into a function has the correct format? The correct format is "8:30:00" or "16:00:00"
Something like:
string_format = "%h%m%s"
if input_data == string_format:
do this
else:
error
-
You can do it by regex or one of date utils to parse it for youAmi Hollander– Ami Hollander2018-04-13 04:54:07 +00:00Commented Apr 13, 2018 at 4:54
-
See stackoverflow.com/questions/1322464/… I think this question is so a duplicate.Arpad Horvath -- Слава Україні– Arpad Horvath -- Слава Україні2018-04-13 05:20:42 +00:00Commented Apr 13, 2018 at 5:20
-
Possible duplicate of python time format checkSiHa– SiHa2018-04-13 06:44:53 +00:00Commented Apr 13, 2018 at 6:44
Add a comment
|
2 Answers
You can do it without using regex. Python has strptime() method which parses a string representing a time according to a format. If string cannot be parsed according to format, or if it has excess data after parsing, ValueError is raised.
Here is the code:
import time
given_time = "10:30:45"
try:
time.strptime(given_time, '%H:%M:%S')
print("Correct Format")
except ValueError:
print("Incorrect Format")
Here are its formats:
%a - abbreviated weekday name
%A - full weekday name
%b - abbreviated month name
%B - full month name
%c - preferred date and time representation
%C - century number (the year divided by 100, range 00 to 99)
%d - day of the month (01 to 31)
%D - same as %m/%d/%y
%e - day of the month (1 to 31)
%g - like %G, but without the century
%G - 4-digit year corresponding to the ISO week number (see %V).
%h - same as %b
%H - hour, using a 24-hour clock (00 to 23)
%I - hour, using a 12-hour clock (01 to 12)
%j - day of the year (001 to 366)
%m - month (01 to 12)
%M - minute
%n - newline character
%p - either am or pm according to the given time value
%r - time in a.m. and p.m. notation
%R - time in 24 hour notation
%S - second
%t - tab character
%T - current time, equal to %H:%M:%S
%u - weekday as a number (1 to 7), Monday=1. Warning: In Sun Solaris Sunday=1
%U - week number of the current year, starting with the first Sunday as the first day of the first week
%V - The ISO 8601 week number of the current year (01 to 53), where week 1 is the first week that has at least 4 days in the current year, and with Monday as the first day of the week
%W - week number of the current year, starting with the first Monday as the first day of the first week
%w - day of the week as a decimal, Sunday=0
%x - preferred date representation without the time
%X - preferred time representation without the date
%y - year without a century (range 00 to 99)
%Y - year including the century
%Z or %z - time zone or name or abbreviation
%% - a literal % character
1 Comment
kinton
If you need to check many lines, you need to build a high ladder from try-catch blocks. I don't think this is a good pattern.
You can use regex to match the format, then take action depending on if a match is found. Provide re.match() with a pattern and the string you want to check:
import re
strings = ["8:30:00", "16:00:00", "845:00", "aa:bb:00"]
for s in strings:
if re.match("\d{1,2}:\d{2}:\d{2}", s): # Will return True if pattern matches s
print("match: {}".format(s)) # Take action on a matching pattern
else:
print("no match: {}".format(s))
The pattern \d{1,2}:\d{2}:\d{2} will match 1 or 2 digits, colon, 2 digits, colon, and 2 digits
The above will print:
match: 8:30:00
match: 16:00:00
no match: 845:00
no match: aa:bb:00