Target to modify:
Sample ="FST~C~D~170101 FST~C~D~170102 FST~C~D~170103 FST~C~D~170104"
I want to replace "170101","170102","170103","170104" with "170413", "170414","170415","170416"(the current date and days behind) The output should be:
"FST~C~D~170413 FST~C~D~170414 FST~C~D~0415 FST~C~D~170416"
I tried with replace() but failed. I know it is due a "string" is not allowed to be modified. Anyone can help on this!
Because of the nature of your data there, you could probably benefit from slicing your data into variables and adding them to a list or dictionary. From there you can use a for loop to operate on specific values.
This should help with slicing: Is there a way to substring a string in Python?
>>> x = "FST~C~D~170101 FST~C~D~170102 FST~C~D~170103 FST~C~D~170104"
>>> a = x[:7]
>>> print(a)
'FST~C~D~'
>>> b = x[8:13]
>>> print(b)
170101
... continue this with the rest of your data
>>> mydict = {a:b,c:d,e:f,g:h}
Then with a dictionary of your values, operate on them. To do that here's a helpful answer: Replacing values in a Python list/dictionary?
I do hope this helps!
You could use a regex to find the old dates and define a function to calculate the new ones:
import re
from datetime import date, datetime
sample = "FST~C~D~170101 FST~C~D~170102 FST~C~D~170103 FST~C~D~170104"
def parse_yymmdd(yymmdd):
return datetime.strptime(yymmdd, '%y%m%d').date()
first_date = parse_yymmdd('170101')
def replace_date(old_date):
old_date = parse_yymmdd(old_date.group(0))
new_date = date.today() + (old_date - first_date)
return new_date.strftime('%y%m%d')
print(re.sub(r'(?<=FST~C~D~)\d+\b', replace_date, sample))
# "FST~C~D~170413 FST~C~D~170414 FST~C~D~170415 FST~C~D~170416"
