In this article, we will be unveiling techniques to find the length of a Python list. Finding the length actually means fetching the count of data elements in an iterable.

## Technique 1: The len() method to find the length of a list in Python

Python has got in-built method — len() to find the **size of the list** i.e. the length of the list.

The `len() method`

accepts an iterable as an argument and it counts and returns the number of elements present in the list.

**Syntax:**

1 |
len(list) |

**Example:**

1 2 3 |
inp_lst = ['Python','Java','Kotlin','Machine Learning','Keras'] size = len(inp_lst) print(size) |

**Output:**

1 2 |
<span style="color: #008000;"><strong>5 </strong></span> |

## Technique 2: Using Python for loop to get the length

In order to find the length of the list in Python, using for loop is considered as a traditional technique or a naive method in the following manner:

- Declare a counter variable and initialize it to zero.
- Using a for loop, traverse through all the data elements and after encountering every element, increment the counter variable by 1.
- Thus, the length of the array will be stored in the counter variable as the variable will represent the number of elements in the list.

1 2 3 4 |
counter = 0 for item in list: counter+=1 print(counter) |

**Example:**

1 2 3 4 5 6 |
inp_lst = ['Python','Java','Kotlin','Machine Learning','Keras'] size = 0 print("Length of the input string:") for x in inp_lst: size+=1 print(size) |

**Output:**

1 2 3 |
<span style="color: #008000;"><strong>Length of the input string: 5 </strong></span> |

## Technique 3: The length_hint() function to get the length of the list

Python operator module has in-built **length_hint() function** to calculate the total number of elements in the list.

The `operator.length_hint()`

method is used to find the length of an iterable such as list, tuple, dict, etc.

**Syntax:**

1 |
length_hint(iterable) |

**Example:**

1 2 3 4 5 |
from operator import length_hint inp_lst = ['Python','Java','Kotlin','Machine Learning','Keras'] print("Length of the input string:") size = length_hint(inp_lst) print(size) |

**Output:**

1 2 3 |
<span style="color: #008000;"><strong>Length of the input string: 5 </strong></span> |

## Best approach to find length of a Python list

Out of all the methods mentioned above, Python in-built len() method is considered as the best approach by programmers to get the size of the list.

Reason: The `len() function`

requires `O(1) time`

to calculate the size of the list because as list actually is an object so thus, it has memory space available to store the size.

## Conclusion

Thus, in this article, we have understood the different ways to calculate the length of a Python list.