Data Science Portfolio

Strings

Basics

• Strings represent a sequence of text characters
• They are created by enclosing characters in quotes
  • Single quotes and double quotes are treated the same in Python

Create a string with single quotes and assign it to a variable

my_str = 'Hello World'

print(my_str)

Hello World

Create a string with double quotes and assign it to a variable

my_str = "Hello World"

print(my_str)

Hello World

Accessing String Elements

• Square brackets and the index (or indices) are used together to access string elements
• A single character is also treated as a substring, or just a string of length one

Access substrings of a string

my_str = "Hello World"

print(my_str[0])

print(my_str[0:5])

H
Hello

Modifying Strings

• A string can be modified by reassigning a string variable to a different string

Create a new string using a substring of another string

my_str = "Hello World"

new_str = my_str[:6] + "Universe"

print(new_str)

Hello Universe

String Formatting Operator

• The string formatting operator “%” can be used to set strings dynamically
• This operator is used to format a set of variables enclosed in a tuple
• The format variable is used in place of the variable element in the string
  • This variable can take on different types
    • “%s” is used for a string
    • “%d” is used for an integer

Simple string formatting example

print("My name is %s and I am %d years old." % ("John", 30))

My name is John and I am 30 years old.