any(iterable, /)
如果 iterable 的任一元素為真，回傳 True。如果 iterable 是空的，則回傳 False
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print(any(['a', 'b', 'c', 'd'])) # True print(any(['a', 'b', '', 'd'])) # True print(any([0, False, ''])) # False print(any([0, 0, 0, 0])) # False print(any([0, 0, 1, 0])) # True print(any([])) # False |
PS:
all: iterable 內所有元素皆為True則回傳 True，若iterable 為空則回傳True
all(iterable, /)
當iterable內所有元素為True時或iterable為空，則回傳True
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print(all(['a', 'b', 'c', 'd'])) # True print(all(['a', 'b', '', 'd'])) # False print(all([0, 1, 1, 1])) # False print(all([])) # True |
PS:
any: 任一元素為True時回傳True，iterable為空則回傳False
zip(*iterables, strict=False)
*iterables:
可迭代物件
strict:
當設定為True，若可迭代物件長度不一致時，會產生異常
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x = ['a', 'b', 'c'] y = [1, 2, 3] print(list(zip(x, y))) # [('a', 1), ('b', 2), ('c', 3)] z = [4, 5, 6, 7] print(list(zip(x, z, strict=True))) # ValueError: zip() argument 2 is longer than argument 1 |
使用zip搭配for loop，可非常簡潔地產生座標給PyQt QGridLayout使用
positions list中的元素為 tuple，zip產生的position也是tuple
拆解:
positions list: [(0, 0), (0, 1), …, (4, 3)]
list(zip(positions, name)): [((0, 0), ‘Cls’), ((0, 1), ‘Black’), …, ((4, 3), ‘+’)]
position: (0, 0), …, (4, 3)
name: Cls, Back, …, +
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# -*- coding: utf-8 -*- import sys from PyQt5.QtWidgets import QApplication, QWidget, QGridLayout, QPushButton class Winform(QWidget): def __init__(self, parent=None): super(Winform, self).__init__(parent) self.initUI() def initUI(self): grid = QGridLayout() self.setLayout(grid) names = ['Cls', 'Back', '', 'Close', '7', '8', '9', '/', '4', '5', '6', '*', '1', '2', '3', '-', '0', '.', '=', '+'] positions = [(i, j) for i in range(5) for j in range(4)] for position, name in zip(positions, names): if name == '': continue button = QPushButton(name) # addWidget(QWidget widget, int row, int col, int alignment=0) # position: (0, 0) ~ (4, 3) # *position: 0 0 ~ 4 3 grid.addWidget(button, *position) self.move(300, 150) self.setWindowTitle('網格佈局') if __name__ == "__main__": app = QApplication(sys.argv) form = Winform() form.show() sys.exit(app.exec_()) |
map(function, iterable, *iterables)
返回結果是一個列表，不改變原有的list，而是返回一個新的list
function:
回傳的是一個函數名，可以是python內置的，也可以是自定義
iterable:
回傳的是一個可以迭代的對象，例如列表、元組、字符串
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a = (1, 2, 3, 4, 5) b = [1, 2, 3, 4, 5] c = "abcdef" print(map(str, a)) # <map object at 0x00000281B591B0B8> 返回一個map對象 print(list(map(str, a))) # ['1', '2', '3', '4', '5'] 將map對象列表顯示出來 print(map(str, b)) # <map object at 0x00000230BB7F3358> print(list(map(str, b))) # ['1', '2', '3', '4', '5'] print(map(str, c)) # <map object at 0x00000230BB7FB0B8> print(list(map(str, c))) # ['a', 'b', 'c', 'd', 'e', 'f'] |