Common Python Built‑in Functions with Example Code

print() – prints information to the console. print("Hello, World!")

len() – returns the length of a collection. my_list = [1, 2, 3, 4, 5] print(len(my_list)) # 5

type() – obtains the type of an object. var = 10 print(type(var)) #

int(), float(), str() – convert between string, integer and float types. num_str = "123" num_int = int(num_str) print(num_int) # 123 num_float_str = "123.45" num_float = float(num_float_str) print(num_float) # 123.45 num = 123 num_str_converted = str(num) print(num_str_converted) # "123"

list(), tuple(), set() – create or convert to common containers. my_tuple = (1, 2, 3) my_list_from_tuple = list(my_tuple) print(my_list_from_tuple) # [1, 2, 3] my_list = [1, 2, 2, 3, 4] my_set_from_list = set(my_list) print(my_set_from_list) # {1, 2, 3, 4} my_dict = dict([('a', 1), ('b', 2)]) print(my_dict) # {'a': 1, 'b': 2}

range(), sum(), min(), max() – generate numeric sequences and compute aggregates. numbers = range(1, 6) print(sum(numbers)) # 15 print(min(numbers)) # 1 print(max(numbers)) # 5

input() – read user input from the console. user_input = input("请输入您的名字: ") print("你好，" + user_input + "!")

round() – round a floating‑point number to a given precision. rounded_num = round(3.14159, 2) print(rounded_num) # 3.14

enumerate() – iterate with index and value. fruits = ['apple', 'banana', 'cherry'] for index, fruit in enumerate(fruits): print(index, fruit)

zip() – iterate over multiple iterables in parallel. names = ['Alice', 'Bob', 'Charlie'] ages = [24, 30, 22] for name, age in zip(names, ages): print(name, "is", age, "years old.")

sorted() – return a sorted list. unsorted_list = [3, 1, 4, 1, 5, 9, 2, 6] sorted_list = sorted(unsorted_list) print(sorted_list) # [1, 1, 2, 3, 4, 5, 6, 9]

any(), all() – logical checks over iterables. bool_list = [True, False, True] print(any(bool_list)) # True print(all(bool_list)) # False

bin(), oct(), hex() – convert an integer to binary, octal, or hexadecimal string. decimal_number = 10 print(bin(decimal_number)) # 0b1010 print(oct(decimal_number)) # 0o12 print(hex(decimal_number)) # 0xA

chr(), ord() – convert between Unicode code points and characters. char = chr(97) # 'a' print(char) # a unicode_point = ord('€') print(unicode_point) # 8364

help() and dir() – inspect objects and obtain documentation. print(dir(list)) help(list.append)

input() with type conversion – read and convert user input. age = int(input("请输入您的年龄: ")) print("您输入的年龄是:", age)

round() for floating‑point precision – another example. number = 3.14159 rounded = round(number, 3) print(rounded) # 3.142

range() in a loop – iterate over a sequence of numbers. for i in range(5): print(i, end=' ') # Output: 0 1 2 3 4