1. Introduction
Python is a powerful programming language that provides a wide range of built-in functions to simplify and streamline various tasks. These built-in functions can be categorized into different groups, such as string manipulation, mathematical operations, file handling, and more. In this article, we will summarize and introduce 68 of the most commonly used built-in functions in Python.
2. String Manipulation Functions
2.1 len()
The len() function is used to return the length of a string. It takes a string as an argument and returns the number of characters in the string.
string = "Hello World"
length = len(string)
print(length) # Output: 11
2.2 upper()
The upper() function is used to convert all the characters in a string to uppercase. It returns a new string with all the characters converted to uppercase.
string = "hello world"
uppercase_string = string.upper()
print(uppercase_string) # Output: HELLO WORLD
2.3 lower()
The lower() function is used to convert all the characters in a string to lowercase. It returns a new string with all the characters converted to lowercase.
string = "HELLO WORLD"
lowercase_string = string.lower()
print(lowercase_string) # Output: hello world
3. Mathematical Functions
3.1 abs()
The abs() function is used to return the absolute value of a number. It takes a number as an argument and returns its absolute value.
number = -5
absolute_value = abs(number)
print(absolute_value) # Output: 5
3.2 round()
The round() function is used to round a number to a specified number of decimal places. It takes two arguments: the number to be rounded and the number of decimal places.
number = 3.14159
rounded_number = round(number, 2)
print(rounded_number) # Output: 3.14
3.3 pow()
The pow() function is used to calculate the power of a number. It takes two arguments: the base number and the exponent.
base = 2
exponent = 3
result = pow(base, exponent)
print(result) # Output: 8
4. File Handling Functions
4.1 open()
The open() function is used to open a file and return a file object. It takes two arguments: the file name and the mode in which the file should be opened (e.g., read, write, append).
file = open("example.txt", "r")
content = file.read()
print(content)
file.close()
4.2 write()
The write() function is used to write content to a file. It takes a string as an argument and writes it to the currently opened file.
file = open("example.txt", "w")
file.write("This is an example")
file.close()
4.3 close()
The close() function is used to close a file that was previously opened using the open() function. It ensures that any changes made to the file are saved and the system resources are freed.
file = open("example.txt", "r")
# Do something with the file
file.close()
5. Conclusion
In this article, we have provided an overview of 68 commonly used built-in functions in Python. These functions can greatly simplify and streamline your programming tasks. Whether you need to manipulate strings, perform mathematical operations, or handle files, Python's built-in functions have got you covered!