what is .format in python 3 code example

Example 1: python string format

string_a = "Hello"
string_b = "Cena"

# Index based:
print("{0}, John {1}"
      .format(string_a, string_b))
# Object based:
print("{greeting}, John {last_name}"
      .format(greeting=string_a, last_name=string_b))

Example 2: formatter in python

#TO  know this execute  and check
username,password = "GOOGLE","google"
#a. %  first type
print("User name=%s User password=%s"%(username,password))
#b. {}  second type
print("User name={} User password={}".format(username,password
#c. f  third type
print(f"User name={username} User password={password}")
print(f"User name={username} \nUser password={password}"