时间:2021-07-01 10:21:17 帮助过:107人阅读
很多人都知道 Python 是一种高级编程语言,其设计的核心理念是代码的易读性,以及允许编程者通过若干行代码轻松表达想法创意。实际上,很多人选择学习 Python 的首要原因是其编程的优美性,用它编码和表达想法非常自然。此外,Python 的编写使用方式有多种,数据科学、网页开发、机器学习皆可使用 Python。Quora、Pinterest 和 Spotify 都使用 Python 作为其后端开发语言。
交换变量值
- """pythonic way of value swapping"""
- a, b=5,10
- print(a,b)
- a,b=b,a
- print(a,b)
将列表中的所有元素组合成字符串
- a=["python","is","awesome"]
- print(" ".join(a))
查找列表中频率最高的值
- """most frequent element in a list"""
- a=[1,2,3,1,2,3,2,2,4,5,1]
- print(max(set(a),key=a.count))
- """using Counter from collections"""
- from collections import Counter
- cnt=Counter(a)
- print(cnt.most_commin(3))
检查两个字符串是不是由相同字母不同顺序组成
- from collections import Counter
- Counter(str1)==Counter(str2)
反转字符串
- """reversing string with special case of slice step param"""
- a ='abcdefghij k lmnopqrs tuvwxyz 'print(a[ ::-1] )
- """iterating over string contents in reverse efficiently."""
- for char in reversed(a):
- print(char )
- """reversing an integer through type conversion and slicing ."""
- num = 123456789
- print( int( str(num)[::1]))
反转列表
- """reversing list with special case of slice step param"""
- a=[5,4,3,2,1]
- print(a[::1])
- """iterating over list contents in reverse efficiently ."""
- for ele in reversed(a):
- print(ele )
转置二维数组
- """transpose 2d array [[a,b], [c,d], [e,f]] -> [[a,c,e], [b,d,f]]"""
- original = [['a', 'b'], ['c', 'd'], ['e', 'f']]
- transposed = zip( *original )
- print(list( transposed) )
链式比较
- """ chained comparison with all kind of operators"""
- b =6
- print(4< b < 7 )
- print(1 == b < 20)
链式函数调用
- """calling different functions with same arguments based on condition"""
- def product(a, b):
- return a * b
- def add(a, b):
- return a+ b
- b =True
- print((product if b else add)(5, 7))
复制列表
- """a fast way to make a shallow copy of a list"""
- b=a
- b[0]= 10
- """ bothaandbwillbe[10,2,3,4,5]"""
- b = a[:]b[O] = 10
- """only b will change to [10, 2, 3, 4, 5] """
- """copy list by typecasting method"""
- a=[l,2,3,4,5]
- print(list(a))
- """using the list.copy( ) method ( python3 only )"""
- a=[1,2,3,4,5]
- print(a.copy( ))
- """copy nested lists using copy. deepcopy"""
- from copy import deepcopy
- l=[l,2],[3,4]]
- l2 = deepcopy(l)
- print(l2)
字典get法
- """ returning None or default value, when key is not in dict"""
- d = ['a': 1, 'b': 2]
- print(d.get('c', 3))
通过「键」排序字典元素
- """Sort a dictionary by its values with the built-in sorted( ) function and a ' key' argument ."""
- d = {'apple': 10, 'orange': 20, ' banana': 5, 'rotten tomato': 1)
- print( sorted(d. items( ), key=lambda x: x[1]))
- """Sort using operator . itemgetter as the sort key instead of a lambda"""
- from operator import itemgetter
- print( sorted(d. items(), key=itemgetter(1)))
- """Sort dict keys by value"""
- print( sorted(d, key=d.get))
For Else
- """else gets called when for loop does not reach break statement"""
- a=[1,2,3,4,5]
- for el in a:
- if el==0:
- break
- else:
- print( 'did not break out of for loop' )
转换列表为逗号分割符格式
- """converts list to comma separated string"""
- items = [foo', 'bar', 'xyz']
- print (','.join( items))
- """list of numbers to comma separated"""
- numbers = [2, 3, 5, 10]
- print (','.join(map(str, numbers)))
- """list of mix data"""
- data = [2, 'hello', 3, 3,4]
- print (','.join(map(str, data)))
合并字典
- """merge dict's"""
- d1 = {'a': 1}
- d2 = {'b': 2}
- # python 3.5
- print({**d1, **d2})
- print(dict(d1. items( ) | d2. items( )))
- d1. update(d2)
- print(d1)
列表中最小和最大值的索引
- """Find Index of Min/Max Element .
- """
- lst= [40, 10, 20, 30]
- def minIndex(lst):
- return min( range(len(lst)), key=lst.. getitem__ )
- def maxIndex(lst):
- return max( range( len(lst)), key=lst.. getitem__ )
- print( minIndex(lst))
- print( maxIndex(lst))
移除列表中的重复元素
- """remove duplicate items from list. note: does, not preserve the original list order"""
- items=[2,2,3,3,1]
- newitems2 = list(set( items))
- print (newitems2)
- """remove dups and, keep. order"""
- from collections import OrderedDict
- items = ["foo", "bar", "bar", "foo"]
- print( list( orderedDict.f romkeys(items ).keys( )))
以上,就是关于Python编程中的17个实用且有效的小操作
以上就是Python学习之17个关于Python的小技巧的详细内容,更多请关注Gxl网其它相关文章!