《本办法学python——习题37》
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便签堆了一桌,写一写理一理
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一. 关键字
1.判断、循环
——(for,while,if,elif,else,in,and,or,not)
1.1. 判断
and,or,not 用于判断条件的成立与否。
1.2. 循环
for循环——
for A in B/ for A range(c, d, f):
content
return X, Y, Z..
while循环——
while True:
content
return X,Y,Z..
1.3.补充——循环
break.(终止循环)
1 def test(a, b): 2 a = int(raw_input("> ")) 3 b = int(raw_input(">> ")) 4 5 while True: 6 if a >= b: 7 print a 8 break 9 else: 10 a += 1 11 12 print "Test is over." 13 14 15 num1 = 0 16 num2 = 0 17 test(num1, num2)
2.函数和模块
—— def, return,lamda, global; from, import, as
3.几个其他关键字
with
with open("test.txt") as file: print file.read()
assert:判断能否插入,如有无字符串
用法: assert list is None
》》Assertion Error
del:删除list中的字符串
用法: list.del[x,y] # x,y为基数
exec:
a = "print\" this is a test.\"" exec a
4.其他不熟悉的关键字
is(用于判断)
异常:try、finally、except、raise
函数:lambda、pass、class、
其他:yield