You can try any of the below ways-
With REGEX
import pandas as pd
pd.set_option('max_colwidth', 400)
df = pd.DataFrame({'Reviews':['dealer said it does not reimburse dealers for loaners or rentals... so why even be a dealership if they make faulty cars and you re on the line to help customers']})
df['Reviews'] = df['Reviews'].replace('\.+','.',regex=True)
print(df)
With REGEX
import re
regex = r"[.]+"
test_str = "dealer said it does not reimburse dealers for loaners or rentals... so why even be a dealership if they make faulty cars and you re on the line to help customers"
subst = "."
result = re.sub(regex, subst, test_str, 0, re.MULTILINE | re.IGNORECASE)
if result:
print (result)
With REGEX
import re
regex = r"(\W)\1+"
test_str = "dealer said it does not reimburse dealers for loaners or rentals... so why even be a dealership if they make faulty cars and you re on the line to help customers"
subst = "\\1"
result = re.sub(regex, subst, test_str, 0, re.MULTILINE)
if result:
print (result)