Python小白必备的8个最常用的内置函数（推荐）

print(*objects, sep=' ', end='', file=sys.stdout, flush=False)

>>> print(1,2,3)1 2 3

>>> print(1,2,3, sep=',')1,2,3

>>> print(1,2,3, sep=',', file=open("hello.txt", "w"))

>>> isinstance(1, (int, str))True>>> isinstance("", (int, str))True>>> isinstance([], dict)False

range([start,] stop [, step]) -> range object

>>> >>> range(5)range(0, 5)>>> >>> list(range(5))[0, 1, 2, 3, 4]>>>

>>> for i in range(3):...   print("hello python")...hello pythonhello pythonhello python

>>> range(1, 10, 2)range(1, 10, 2)>>> list(range(1, 10, 2))[1, 3, 5, 7, 9]

enumerate(iterable, start=0)

>>> for index, value in enumerate("python"):...   print(index, value)...0 p1 y2 t3 h4 o5 n

>>> for index, value in enumerate("python", start=1):...   print(index, value)...1 p2 y3 t4 h5 o6 n

def my_enumerate(sequence, start=0):  n = start  for e in sequence:    yield n, e    n += 1
>>> for index, value in my_enumerate("python"):  print(index, value)0 p1 y2 t3 h4 o5 n

>>> len([1,2,3])3>>> len("python")6>>> if len([]) == 0:    pass

>>> len(True)Traceback (most recent call last): File "<stdin>", line 1, in <module>TypeError: object of type 'bool' has no len()

>>> list(reversed([1,2,3]))[3, 2, 1]

open(file, mode='r', encoding=None)

>>>f = open("test.txt")>>>f.read()...

f = open("test.txt", encoding='utf8')

>>>f = open("hello.text", 'w', encoding='utf8')>>>f.write("hello python"))

f = open("hello.text", 'a', encoding='utf8')f.write("!!!")

>>> sorted([1,4,2,1,0])[0, 1, 1, 2, 4]