Regex function to replace Month texts from the input strings and replace them with numbers
Question:
I’m pretty new to Python and I just started learning Regex. This is a weird one. I’m working on a function to convert an input string which has months init such as ‘January’ and convert it to numerical i.e. ’01’. I understood what I should be doing but I kinda messed up the entire loop and it’s not giving me the appropriate result. Please ignore my stupidity regarding the extremely long if condition.
Here’s my code:
def transform(string):
k=['January','February','March','April','May','June','July','August','September','October','November','December']
l=string
j=l.split()
for i in k:
for a in j:
if a==k:
j=re.sub(r"January", "01", j)
j=re.sub(r"February", "02", j)
j=re.sub(r"March", "03", j)
j=re.sub(r"April", "04", j)
j=re.sub(r"May", "05", j)
j=re.sub(r"June", "06", j)
j=re.sub(r"July", "07", j)
j=re.sub(r"August", "08", j)
j=re.sub(r"September", "09", j)
j=re.sub(r"October", "10", j)
j=re.sub(r"November", "11", j)
j=re.sub(r"December", "12", j)
return (' '.join(j))
else:
return('This is a string without a month in it')
print( transform('I was born on June 24 and my sister was born on May 17') )
# expected output: 'I was born on 06 24 and my sister was born on 05 17'
print( transform('This is a string without a month in it') )
# expected output: 'This is a string without a month in it'
Well. let me explain what I tried to do. I tried to split the input string and look for any equalities with terms in k[] if any just transform the list using re.sub() and then just join to print them. If there isn’t any value in split function which is also in k[] print that there’s no month text.
Please help correct my code. I know i was extremely bad with the loops but I’m seriously working on it. But I do want to use regex substitute to do this problem since that’s what I was trying to learn. Please help.
Answers:
You may use
import re
def transform(text):
dct = {'January':'01','February':'02','March':'03','April':'04','May':'05','June':'06','July':'07','August':'08','September':'09','October':'10','November':'11','December':'12'}
output, n = re.subn(rf'b(?:{"|".join(dct.keys())})b', lambda x: dct[x.group()], text)
if not n:
return('This is a string without a month in it')
else:
return output
print( transform('I was born on June 24 and my sister was born on May 17') )
# => 'I was born on 06 24 and my sister was born on 05 17'
print( transform('This is a string without a month in it') )
# => 'This is a string without a month in it'
See the Python demo
The rf'b(?:{"|".join(dct.keys())})b' results in a pattern that searches for any month name as a whole word – (?:January|February|...) – and once the match is found, the match is passed to the re.subn lambda where the value for the key from the dct dictionary is returned.
Use regex with dictionary data to replace:
import re
text = 'I was born on June 24 and my sister was born on May 17'
def transform(string):
dict_data = {'January': '01', 'February': '02', 'March': '03', 'April': '04', 'May': '05', 'June': '06', 'July': '07',
'August': '08', 'September': '09', 'October': '10', 'November': '11', 'December': '12'}
for key, value in dict_data.items():
string = re.sub(key, value, string)
return string
print(transform(text))
Output:
I was born on 06 24 and my sister was born on 05 17
#example with perl using hash
$_ = "Mar-15 " ;
%mons = (‘JAN’=>"01",’FEB’=>"02",’MAR’=>"03",’APR’=>"04",’MAY’=>"05",’JUN’=>"06",’JUL’=>"07",’AUG’=>"08",’SEP’=>"09",’OCT’=>"10",’NOV’=>"11",’DEC’=>"12");
$_ = uc($_) ;
s/(JAN(?:UARY)?|FEB(?:RUARY)?|MAR(?:CH)?|APR(?:IL)?|MAY|JUN(?:E)?|JUL(?:Y)?|AUG(?:UST)?|SEP(?:TEMBER)?|OCT(?:OBER)?|(NOV|DEC)(?:EMBER)?)/$mons{$1}/egs ;
print $_ ; # 03-15
I’m pretty new to Python and I just started learning Regex. This is a weird one. I’m working on a function to convert an input string which has months init such as ‘January’ and convert it to numerical i.e. ’01’. I understood what I should be doing but I kinda messed up the entire loop and it’s not giving me the appropriate result. Please ignore my stupidity regarding the extremely long if condition.
Here’s my code:
def transform(string):
k=['January','February','March','April','May','June','July','August','September','October','November','December']
l=string
j=l.split()
for i in k:
for a in j:
if a==k:
j=re.sub(r"January", "01", j)
j=re.sub(r"February", "02", j)
j=re.sub(r"March", "03", j)
j=re.sub(r"April", "04", j)
j=re.sub(r"May", "05", j)
j=re.sub(r"June", "06", j)
j=re.sub(r"July", "07", j)
j=re.sub(r"August", "08", j)
j=re.sub(r"September", "09", j)
j=re.sub(r"October", "10", j)
j=re.sub(r"November", "11", j)
j=re.sub(r"December", "12", j)
return (' '.join(j))
else:
return('This is a string without a month in it')
print( transform('I was born on June 24 and my sister was born on May 17') )
# expected output: 'I was born on 06 24 and my sister was born on 05 17'
print( transform('This is a string without a month in it') )
# expected output: 'This is a string without a month in it'
Well. let me explain what I tried to do. I tried to split the input string and look for any equalities with terms in k[] if any just transform the list using re.sub() and then just join to print them. If there isn’t any value in split function which is also in k[] print that there’s no month text.
Please help correct my code. I know i was extremely bad with the loops but I’m seriously working on it. But I do want to use regex substitute to do this problem since that’s what I was trying to learn. Please help.
You may use
import re
def transform(text):
dct = {'January':'01','February':'02','March':'03','April':'04','May':'05','June':'06','July':'07','August':'08','September':'09','October':'10','November':'11','December':'12'}
output, n = re.subn(rf'b(?:{"|".join(dct.keys())})b', lambda x: dct[x.group()], text)
if not n:
return('This is a string without a month in it')
else:
return output
print( transform('I was born on June 24 and my sister was born on May 17') )
# => 'I was born on 06 24 and my sister was born on 05 17'
print( transform('This is a string without a month in it') )
# => 'This is a string without a month in it'
See the Python demo
The rf'b(?:{"|".join(dct.keys())})b' results in a pattern that searches for any month name as a whole word – (?:January|February|...) – and once the match is found, the match is passed to the re.subn lambda where the value for the key from the dct dictionary is returned.
Use regex with dictionary data to replace:
import re
text = 'I was born on June 24 and my sister was born on May 17'
def transform(string):
dict_data = {'January': '01', 'February': '02', 'March': '03', 'April': '04', 'May': '05', 'June': '06', 'July': '07',
'August': '08', 'September': '09', 'October': '10', 'November': '11', 'December': '12'}
for key, value in dict_data.items():
string = re.sub(key, value, string)
return string
print(transform(text))
Output:
I was born on 06 24 and my sister was born on 05 17
#example with perl using hash
$_ = "Mar-15 " ;
%mons = (‘JAN’=>"01",’FEB’=>"02",’MAR’=>"03",’APR’=>"04",’MAY’=>"05",’JUN’=>"06",’JUL’=>"07",’AUG’=>"08",’SEP’=>"09",’OCT’=>"10",’NOV’=>"11",’DEC’=>"12");
$_ = uc($_) ;
s/(JAN(?:UARY)?|FEB(?:RUARY)?|MAR(?:CH)?|APR(?:IL)?|MAY|JUN(?:E)?|JUL(?:Y)?|AUG(?:UST)?|SEP(?:TEMBER)?|OCT(?:OBER)?|(NOV|DEC)(?:EMBER)?)/$mons{$1}/egs ;
print $_ ; # 03-15