The shape using the quotation marks (") allows the developer to insert variables that will be substituted at run time.

But if the string does not have a variable, use quotes (') instead.

Thus, language will not look for variables to substitute, which will reduce the consumption of CPU cycles.

Noncompliant Code Example

# in variables
firstname = "Andrea" # Noncompliant {{Avoid using quotation mark ("), prefer using simple quote (')}}

# in functions
def my_function(name, age):
    print(name + 'is' + age + ' yo.')

my_function("Robert", 12) # Noncompliant {{Avoid using quotation mark ("), prefer using simple quote (')}}

Compliant Solution

# in variables
firstname = 'Andrea'

# in functions
def my_function(name, age):
    print(name + 'is' + age + ' yo.')

my_function('Robert', 12)