Key Built-in Functions in Python
1. print()
The print() function is one of the most commonly used built-in functions in Python. It displays program information or results on the screen, which is very valuable for assessing the output of the Python code.
Example:
Output:
Explanation: Here, the print() function displays the greeting message to the users.
2. len()
The len() is used to return the count of the items that are available in an object. The object can be a string, list, or tuple. This method is very helpful for counting the number of elements.
Example:
Output:
Explanation: Here, len(courses) returns the total length of the list.
3. type()
The type() function in Python returns the type of an object that has been defined. This is very helpful in an instance where it needs to check the data type that an object represents. The datatype could be a string, an integer, or a list, which ensures that the correct expected type of data is being used.
Example:
Output:
Explanation: Here, the type(course) helps in retrieving the type of variable and confirms that it is a string.
4. str()
The str() function is used to convert other data types into a string. It is mainly used to format values into a string, which helps improve readability.
Example:
Output:
Explanation: Here, str(duration) helps in converting the integer 6 into a string, which forms a complete sentence.
5. input()
The input() function allows the user to enter the data requested. This supports the information-gathering process of building interactive programs, in which the programmer can ask users for information during the execution of the code.
Example:
Output:
Explanation: Here, the input() function is used to ask the user which subject they like the most. The input given by the user is stored in the subject variable. The print() statement prints the statement with the subject name.
6. range()
The range() function generates a sequence of numbers, which is mostly used with loops, that will repeat the function or loop through a sequence.
Example:
Output:
Explanation: Here, range(5) helps print numbers that are less than 5.
7. sum()
The sum() function is a combination of an iterable or collection, taking all the items in the iterable and adding them together. This is helpful for quick calculations. It adds all items in an iterable from left to right and returns the total.
Example:
Output:
Explanation: Here, sum(scores) calculates the total sum of the scores.
8. max()
The max() function helps in returning the largest item in an iterable. It accepts multiple arguments or a single iterable It is useful for identifying the element with the highest value in the list, which is very helpful in data analysis.
Example:
Output:
Explanation: Here, max(numbers) helps in finding the largest number in the list here which is 30.
9. min()
The min() function returns the smallest item in an iterable. It accepts multiple arguments or a single iterable. It helps to find the lowest value in a dataset or list, which can be important for analysis.
Example:
Output:
Explanation: Here, min(numbers) returns the smallest number in the list.
10. sorted()
The sorted() function helps in arranging the numbers in an iterable, in ascending or descending order. It is useful in efficiently sorting the data in a particular order for data analysis.
Example:
Output:
Explanation: Here, sorted(values) helps in sorting the list in ascending order.
11. all()
The all() function in Python is used to check whether all the elements in an iterable are true. It is very helpful in checking the condition given by the user. If even one condition is not matched, it will return false.
Example:
Output:
Explanation: Here, the all() function checks whether all the conditions are true, and false is returned as a false condition exists.
12. any()
The any() function checks if any item in an iterable is true. It is useful for determining that at least one condition is True, such as checking users’ inputs.
Example:
Output:
Explanation: Here, the any() function returns True since at least one element is true.
13. dict()
The dict() function creates a dictionary that is a collection of key-value pairs. The data is organised in pairs, such as the name and the corresponding attribute.
Example:
Output:
Explanation: Here, dict() creates a dictionary with student information.
14. list()
The list() function converts an iterable into a list. It is used for transforming the data from any data type to a list-like tuple, into a list for easier manipulation.
Example:
Output:
Explanation: Here, list(numbers_tuple) converts a tuple into a list.
15. zip()
The zip() function combines two or more iterables into tuples. It is useful as it helps in pairing the related data, such as matching names with ages or combining with another dataset. It returns pairs (or groups) of items from each iterable, matching them by position, and stops when the shortest one runs out.
Example:
Output:
Explanation: Here, zip(course_names, durations) displays the name of the course with its corresponding duration.
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Other Common Python Built-in Functions
| Python Function |
Description |
Example |
| ascii() |
Returns a printable representation of an object. |
ascii(‘ä’) → ‘xe4’ |
| bin() |
Converts an integer to a binary string. |
bin(5) → ‘0b101’ |
| bool() |
Converts a value to Boolean. |
bool(1) → True |
| bytearray() |
Returns an array of the given byte size. |
bytearray(5) → bytearray(b’x00x00x00x00x00′) |
| bytes() |
Returns an immutable bytes object. |
bytes(5) → b’x00x00x00x00x00′ |
| callable() |
Checks if the object is callable. |
callable(len) → True |
| compile() |
Compiles source into a code object. |
compile(‘5 + 5’, ‘<string>’, ‘eval’) |
| complex() |
Creates a complex number. |
complex(1, 2) → (1+2j) |
| delattr() |
Deletes an attribute from an object. |
delattr(obj, ‘attr’) |
| dict() |
Creates a Python dictionary. |
dict(a=1, b=2) → {‘a’: 1, ‘b’: 2} |
| dir() |
Returns attributes of an object. |
dir([]) → [‘append’, ‘clear’, …] |
| enumerate() |
Returns an enumerate object. |
enumerate([‘a’, ‘b’]) → (0, ‘a’), (1, ‘b’) |
| eval() |
Executes a given string as Python code. |
eval(‘5 + 5’) → 10 |
| exec() |
Executes dynamically created Python code. |
exec(‘a = 5’) |
| filter() |
Constructs an iterator from the true elements of an iterable. |
filter(lambda x: x > 0, [-1, 2]) → [2] |
| format() |
Formats a value into a string. |
‘{:.2f}’.format(3.14159) → ‘3.14’ |
| frozenset() |
Returns an immutable frozenset object. |
frozenset([1, 2]) → frozenset({1, 2}) |
| getattr() |
Gets the value of a named attribute. |
getattr(obj, ‘attr’) |
| globals() |
Returns the global symbol table as a dictionary. |
globals() → {‘__name__’: ‘__main__’, …} |
| hasattr() |
Checks if an object has a given attribute. |
hasattr(obj, ‘attr’) → True |
| hash() |
Returns the hash value of an object. |
hash(‘hello’) → 99162322 |
| help() |
Invokes the built-in help system. |
help(str) |
| hex() |
Converts an integer to a hexadecimal string. |
hex(255) → ‘0xff’ |
| id() |
Returns the identity of an object. |
id(5) → 9783552 |
| isinstance() |
Checks if an object is an instance of a class. |
isinstance(5, int) → True |
| issubclass() |
Checks if a class is a subclass of another. |
issubclass(bool, int) → True |
| iter() |
Returns an iterator for an object. |
iter([1, 2, 3]) |
| len() |
Returns the length of an object. |
len([1, 2, 3]) → 3 |
| locals() |
Returns the local symbol table as a dictionary. |
locals() → {…} |
| map() |
Applies a function to an iterable. |
list(map(str, [1, 2])) → [‘1’, ‘2’] |
| memoryview() |
Returns a memory view object. |
memoryview(b’abc’) |
| next() |
Returns the next item from an iterator. |
next(iter([1, 2])) → 1 |
| object() |
Creates a featureless object. |
object() |
| oct() |
Converts an integer to octal. |
oct(8) → ‘0o10’ |
| open() |
Opens a file and returns a file object. |
open(‘file.txt’) |
| ord() |
Returns the Unicode code point for a character. |
ord(‘A’) → 65 |
| pow() |
Returns the power of a number. |
pow(2, 3) → 8 |
| print() |
Prints a value to the console. |
print(‘Hello’) |
| property() |
Returns a property object. |
@property def name(self): return self._name |
| range() |
Creates a sequence of integers. |
range(5) → 0, 1, 2, 3, 4 |
| repr() |
Returns a string representation of an object. |
repr(‘test’) → “‘test'” |
| reversed() |
Returns a reversed iterator. |
list(reversed([1, 2])) → [2, 1] |
| set() |
Creates a set. |
set([1, 2, 3]) |
| setattr() |
Sets the value of an object’s attribute. |
setattr(obj, ‘attr’, 5) |
| slice() |
Creates a slice object. |
slice(0, 10) |
| sorted() |
Returns a sorted list from an iterable. |
sorted([3, 1]) → [1, 3] |
| staticmethod() |
Creates a static method. |
@staticmethod def method(): pass |
| str() |
Converts an object to a string. |
str(10) → ’10’ |
| super() |
Returns a proxy for the parent class. |
super().method() |
| tuple() |
Creates a tuple. |
tuple([1, 2]) → (1, 2) |
| type() |
Returns the type of an object. |
type(5) → <class ‘int’> |
| vars() |
Returns the __dict__ attribute of an object. |
vars(obj) |
| __import__() |
Dynamically imports a module. |
__import__(‘os’) |
Mathematical Built-in Functions in Python
| Python Function |
Description |
Example |
| abs() |
Returns the absolute (positive) value of a number. |
abs(-10) → 10 |
| divmod() |
Returns quotient and remainder as a tuple. |
divmod(10, 3) → (3, 1) |
| float() |
Converts a number or string to a float. |
float(“3.14”) → 3.14 |
| int() |
Converts a number or string to an integer. |
int(3.9) → 3 |
| max() |
Returns the largest value from the items. |
max(4, 9, 1) → 9 |
| min() |
Returns the smallest value from the items. |
min(4, 9, 1) → 1 |
| pow() |
Returns x raised to the power y. |
pow(2, 3) → 8 |
| round() |
Rounds a number to the nearest integer. |
round(4.6) → 5 |
| sum() |
Adds all items in an iterable. |
sum([1, 2, 3]) → 6 |
| complex() |
Creates a complex number. |
complex(2, 3) → (2+3j) |
Best Practices for Using Built-in Functions
- Know the function: The right function has to be used for performing operations such as using the sum() for adding numbers or the len() for counting the items. This helps in saving time.
- Using built-in functions first: The built-in functions help in performing an operation faster compared to writing the code from scratch.
- Avoid unnecessary code: The custom functions need not be created when inbuilt functions like max(), abs(), or round are already present to perform a particular operation.
- Optimise function usage: Multiple functions can be combined, like round(sum(nums)/len(nums)), which helps in calculating the average easily.
- Check before using: Checking typos must be done before you can use a built-in function. For example, int(“abc”). The use of try-except blocks can help.
- Write clear code: Using proper and meaningful variable names is very important when using the built-in functions to make the Python code simpler and easier to understand.
Avoiding Repetitive Operations with Built-in Functions in Python
The built-in functions like sum(), max(), and min() are very useful and helpful in avoiding repetitive operations by removing the need for addition of manual loops. These functions help in making the Python code simple, readable, and more efficient. They are also helpful in writing error-free code while saving time with proper logic.
Example Without Built-In Function:
Output:
Explanation: Here, the loop has to be added manually to add up the prices, which can make the code lengthier and less efficient.
Example With Built-In Function:
Using sum() to do the same operation:
Output:
Explanation: Here, the sum() function adds the prices of all items and returns the total in just one line, efficiently.
Real-World Examples for Built-in Functions in Python
1. Analysing Daily Sales Data
The built-in functions can be used for determining the average, the highest, and the lowest sales in a day.
Example:
Output:
Explanation: Here, sum(), len(), max(), and min() are used to calculate the average, highest, and lowest sales of the day.
2. Cleaning and Sorting Usernames
The built-in function in Python can be used to clean and sort the data.
Example:
Output:
Explanation: Here, strip(), lower(), sorted(), and list comprehension are used to clean and sort usernames alphabetically.
3. Displaying Product Info from Inventory
The built-in function in Python can be used to find and display the item that has the highest stock in the inventory.
Example:
Output:
Explanation: Here, max(), key=, get(), and title() are used to find and format the most stocked product for display.
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Conclusion
The Python built-in functions play a key role in writing cleaner, readable, and efficient code. They are very useful in performing common operations like handling the input, converting the data types, and performing calculations with just a single line of code. Using the built-in functions in Python reduces the repetition and makes the code efficient. They are also helpful in solving real-world issues such as analysing the data, managing the inventory, and many other similar applications. Learning and applying them properly makes Python coding faster and easier.
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