• python基础2


    • 集合

    a.特点:具有无序性,单一性,不可重复性

    b.用法:

      b1.pop(随机删除)  remove(删除不存在元素会报错)  discard(删除不存在元素不会报错) 三者的区别

    s={1,2,3,'Hacker_Teen','ugly','I'}
    #i=0
    #while i<len(s):
    #    s.pop()
    #    print(s)
    #    i=i+1
    #------------------------***-------------------
    #s.remove('ugly')
    #print(s)
    #------------------------***-------------------
    s.discard('3')
    print(s)
    

      b2.集合关系的交、并、差、交叉补集集的运算

    python_study = {'wjc','xz','lz','wjc'}
    C_study      = {'wjc','xz','gxq','cxf'}
    py_1 = set(python_study)
    C_1  = set(C_study)
    print(py_1)
    print(C_1)
    #----------------取交集------------
    #print(py_1.intersection(C_1))
    #print((py_1)&(C_1))
    #----------------取并集------------
    #print(py_1.union(C_1))
    #print(py_1|C_1)
    #----------------取差集------------
    #print(py_1.difference(C_1))
    #print(py_1-C_1)
    #----------------交差补集------------
    #print(py_1.symmetric_difference(C_1))
    #print(py_1^C_1)
    

      b3.字符串格式化

    #----------------字符串格式化------------
    #self_introduce='I am %s,my age is %d'%('Hacker_Teen',21)
    #print(self_introduce)
    #print('percen%.2f'%98.67432)
    #------------打印百分号------------------
    #print('percen %.2f %%'%98.67432)
    #-------------用字典传输-------------------
    #self_introduce='I am %(name)s,my age is %(age)d'%({'name':'Hacker_Teen','age':21})
    #print(self_introduce)
    #----------------采用分隔符------------
    print('wjc','xz','lz','gxq',sep=':')

      b4.format的用法

    #--------------format的用法---------------
    li=['Hacker_Teen',21,'coding']
    di={'name':'Hacker_Teen','age':21,'hobby':'coding'}
    #print('I am {0}.Age is {1}.My hobby is {2}'.format('Hacker_Teen',21,'coding'))
    #print('I am {name}.Age is {age}.My hobby is {hobby}'.format(name='Hacker_Teen',age=21,hobby='coding'))
    #test1='I am {:s}.Age is {:d}.My hobby is {:s}'.format(*li)
    #print(test1)
    test2='I am {name}.Age is {age}.My hobby is {hobby}'.format(**di)
    print(test2)
    
    •   函数
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  • 原文地址:https://www.cnblogs.com/hackerteen/p/10232370.html
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