CodeBlanks Logo Icon CodeBlanks
Login Register

in and count

Learn membership with in and counting with count.

in and count

in checks whether an item is in the list. count counts how many of an item exist:

cart = ["Apple", "Bread", "Apple"]
print("Apple" in cart)    # True
print(cart.count("Apple"))  # 2

in returns True/False; count returns a number. These methods are very handy for content searches.

Searching and counting

in and count are useful together: first check whether the item exists with in, then count how many with count:

cart = ["Apple", "Bread", "Apple", "Milk"]
if "Apple" in cart:
    print("Has Apple:", cart.count("Apple"))

This pattern is common in stock control and content search.

Practice Print in and count

Assign cart = ["Apple", "Bread", "Apple"]. Print print("Apple" in cart) and print(cart.count("Apple")).

Starter code

main.py
# in and count

Sample solution

main.py
cart = ["Apple", "Bread", "Apple"]
print("Apple" in cart)
print(cart.count("Apple"))

Expected output

True
2

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 What does cart.count("Apple") return (cart has 2 Apples)?

  • "Apple"
  • True
  • 2 Correct answer
  • Error

Explanation: count counts how many of the item: 2.

2 Complete the in check

Question 
cart = ["Apple", "Bread"]
print("Apple" ____ cart)
Answer 
cart = ["Apple", "Bread"]
print("Apple" in cart)

Explanation: in checks whether the item is in the list.

3 Match the search methods

Term Meaning
in Presence check
count Item count
len Length
index Item position

All lessons in Beginner

1 Python basics

  1. What is Python?
  2. REPL and print
  3. Comments
  4. Indentation blocks
  5. python -c and scripts
  6. Summary - Python basics

2 Variables

  1. Variable assignment
  2. Multiple assignment
  3. Naming variables
  4. id and type
  5. Swapping variables
  6. Summary - Variables

3 Data types

  1. int and float
  2. bool
  3. str basics
  4. None
  5. Type conversion
  6. Summary - Data types

4 Project: Calculator

  1. Project design
  2. Add/subtract
  3. Multiply/divide
  4. Error handling
  5. Putting it together

5 Operators

  1. Arithmetic
  2. Comparison
  3. Logical
  4. Bitwise
  5. Membership and identity
  6. Summary - Operators

6 String basics

  1. f-string
  2. Concatenation
  3. str.format
  4. Raw strings
  5. Triple-quote
  6. Summary - String basics

7 Conditionals

  1. The if statement
  2. elif and else
  3. Nested if
  4. Truthiness
  5. Conditional expression
  6. Summary - Conditionals

8 Loops

  1. The for loop
  2. range
  3. The while loop
  4. break and continue
  5. Loop else
  6. Summary - Loops

9 Project: Shopping cart

  1. Cart design
  2. Adding items
  3. Calculating totals
  4. Updating quantity
  5. Putting it together

10 Lists

  1. Declaring lists
  2. Index and slice
  3. List methods
  4. in and count
  5. Sorting lists
  6. Summary - Lists

11 List comprehension

  1. Comprehension basics
  2. Filtered comprehension
  3. Dict and set comprehension
  4. Nested comprehension
  5. Generator expression
  6. Summary - List comprehension

12 Tuple, set and dict

  1. Tuple
  2. Set
  3. Dict basics
  4. Dict methods
  5. Dict comprehension
  6. Summary - Tuple, set and dict

13 Functions

  1. def
  2. return
  3. Docstring
  4. Default parameters
  5. *args and **kwargs
  6. Summary - Functions

14 Function parameters

  1. Positional parameters
  2. Keyword parameters
  3. Keyword-only
  4. Positional-only
  5. Type hints basics
  6. Summary - Function parameters

15 Project: To-do CLI

  1. Task model
  2. Adding tasks
  3. Listing tasks
  4. Completing tasks
  5. Putting it together

16 Advanced string methods

  1. split and join
  2. strip, lstrip, rstrip
  3. replace
  4. find and index
  5. startswith, endswith
  6. Summary - Advanced strings

17 Input and output

  1. input()
  2. int/float conversion
  3. print parameters
  4. f-string formatting
  5. sys.argv
  6. Summary - Input and output

18 Error handling

  1. try/except
  2. else and finally
  3. raise
  4. Exception hierarchy
  5. Custom exceptions
  6. Summary - Error handling

19 Modules

  1. import
  2. from import
  3. as alias
  4. __name__ == '__main__'
  5. Standard library
  6. Summary - Modules

20 Beginner final

  1. Project design
  2. Data model
  3. Business logic
  4. Error handling
  5. Putting it together