How can I achieve this without using if operator and huge multiline constructions?

Example:

around $98 million last week
above $10 million next month
about €5 billion past year
after £1 billion this day

Convert to

around 98 million dollars last week
above 10 million dollars next month
about 5 billion euros past year
after 1 billion pounds this day

CodePudding user response：

You probably have more cases than this so the regular expression may be too specific if you have more cases, but re.sub can be used with a function to process each match and make the correct replacement. Below solves for the cases provided:

import re

text = '''\
around $98 million last week
above $10 million next month
about €5 billion past year
after £1 billion this day
'''

currency_name = {'$':'dollars', '€':'euros', '£':'pounds'}

def replacement(match):
    # group 2 is the digits and million/billon,
    # tack on the currency type afterward using a lookup dictionary
    return f'{match.group(2)} {currency_name[match.group(1)]}'

# capture the symbol followed by digits and million/billion
print(re.sub(r'([$€£])(\d  [mb]illion)\b', replacement, text))

Output:

around 98 million dollars last week
above 10 million dollars next month
about 5 billion euros past year
after 1 billion pounds this day

CodePudding user response：

You could make a dictionary mapping currency symbol to name, and then generate the regexes. Note that these regexes will only work for something in the form of a number and then a word.

import re
CURRENCIES = {
    r"\$": "dollars", # Note the slash; $ is a special regex character
    "€": "euros",
    "£": "pounds",
}
REGEXES = []
for symbol, name in CURRENCIES.items():
    REGEXES.append((re.compile(rf"{symbol}(\d  [^\W\d_] )"), rf"\1 {name}"))
text = """around $98 million last week
above $10 million next month
about €5 billion past year
after £1 billion this day"""
for regex, replacement in REGEXES:
    text = regex.sub(replacement, text)

CodePudding user response：

It's useful in a case like this to remember that re.sub can accept a lambda rather than just a string.

The following requires Python 3.8 for the := operator.

s = "about €5 billion past year"

re.sub(r'([€$])(\d )\s ([mb]illion)', 
       lambda m: f"{(g := m.groups())[1]} {g[2]} {'euros' if g[0] == '€' else 'dollars'}", 
       s)
# 'about 5 billion euros past year'

CodePudding user response：

this question was partially solved in different questions:

please see this

My suggestions:

string = "around $98 million last week"
new_string = re.sub(r"[^a-zA-Z0-9]"," ",string)
print(new_string)