Python 语法糖
\\,换行连接
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s = \’\’s += \’a\’ + \’b\’ + \’c\’n = 1 + 2 + 3# 6 |
while,for 循环外的 else
如果 while 循环正常结束(没有break退出)就会执行else。
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num = [1,2,3,4]mark = 0while mark < len(num): n = num[mark] if n % 2 == 0: print(n) # break mark += 1else: print(\”done\”) |
zip() 并行迭代
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a = [1,2,3]b = [\’one\’,\’two\’,\’three\’]list(zip(a,b))# [(1, \’one\’), (2, \’two\’), (3, \’three\’)] |
列表推导式
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x = [num for num in range(6)]# [0, 1, 2, 3, 4, 5]y = [num for num in range(6) if num % 2 == 0]# [0, 2, 4] # 多层嵌套rows = range(1,4)cols = range(1,3)for i in rows: for j in cols: print(i,j)# 同rows = range(1,4)cols = range(1,3)x = [(i,j) for i in rows for j in cols] |
字典推导式
{ key_exp : value_exp fro expression in iterable }
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#查询每个字母出现的次数。strs = \’Hello World\’s = { k : strs.count(k) for k in set(strs) } |
集合推导式
{expression for expression in iterable }
元组没有推导式
本以为元组推导式是列表推导式改成括号,后来发现那个 生成器推导式。
生成器推导式
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>>> num = ( x for x in range(5) )>>> num...:<generator object <genexprn-i\”>num...:<generator object <genexpr15px !important;\”>
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s = \’\’s += \’a\’ + \’b\’ + \’c\’n = 1 + 2 + 3# 6 |
while,for 循环外的 else
如果 while 循环正常结束(没有break退出)就会执行else。
123456789
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num = [1,2,3,4]mark = 0while mark < len(num): n = num[mark] if n % 2 == 0: print(n) # break mark += 1else: print(\”done\”) |
zip() 并行迭代
1234
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a = [1,2,3]b = [\’one\’,\’two\’,\’three\’]list(zip(a,b))# [(1, \’one\’), (2, \’two\’), (3, \’three\’)] |
列表推导式
123456789101112131415
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x = [num for num in range(6)]# [0, 1, 2, 3, 4, 5]y = [num for num in range(6) if num % 2 == 0]# [0, 2, 4] # 多层嵌套rows = range(1,4)cols = range(1,3)for i in rows: for j in cols: print(i,j)# 同rows = range(1,4)cols = range(1,3)x = [(i,j) for i in rows for j in cols] |
字典推导式
{ key_exp : value_exp fro expression in iterable }
123
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#查询每个字母出现的次数。strs = \’Hello World\’s = { k : strs.count(k) for k in set(strs) } |
集合推导式
{expression for expression in iterable }
元组没有推导式
本以为元组推导式是列表推导式改成括号,后来发现那个 生成器推导式。
生成器推导式
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>>> num = ( x for x in range(5) )>>> num...:<generator object <genexpron-5812b14b3a777804821015-7\”> # break mark += |
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