String manipulation

str.len

df=tweets[tweets["content"].str.len()>15][["tweet_id"]]

str.contains

df = patients[patients['conditions'].str.contains(r'(^DIAB1|\sDIAB1)', na=False)] # (1)

1. \s matches whitespace (spaces, tabs and new lines)

str.match

pattern = r'^[a-zA-Z][a-zA-Z0-9_.-]*@leetcode\.com$'

# Filter valid emails
df = users[users['mail'].str.match(pattern, na=False)]

str.capitalize

users['name'] = users['name'].str.capitalize()`  # (1)

1. • Series.str.lower: Converts all characters to lowercase.
   • Series.str.upper: Converts all characters to uppercase.
   • Series.str.title: Converts first character of each word to uppercase and remaining to lowercase.
   • Series.str.capitalize: Converts first character to uppercase and remaining to lowercase.
   • Series.str.swapcase: Converts uppercase to lowercase and lowercase to uppercase.
   • Series.str.casefold: Removes all case distinctions in the string.

start with

df['employee_name'].startswith('M')