函数练习题答案

#题目一
def modify_file(filename,old,new):
    import os
    with open(filename,'r',encoding='utf-8') as read_f,\
        open('.bak.swap','w',encoding='utf-8') as write_f:
        for line in read_f:
            if old in line:
                line=line.replace(old,new)
            write_f.write(line)
    os.remove(filename)
    os.rename('.bak.swap',filename)

modify_file('/Users/jieli/PycharmProjects/爬虫/a.txt','alex','SB')

#题目二
def check_str(msg):
    res={
        'num':0,
        'string':0,
        'space':0,
        'other':0,
    }
    for s in msg:
        if s.isdigit():
            res['num']+=1
        elif s.isalpha():
            res['string']+=1
        elif s.isspace():
            res['space']+=1
        else:
            res['other']+=1
    return res

res=check_str('hello name:aSB passowrd:alex3714')
print(res)


#题目三：略

#题目四
def func1(seq):
    if len(seq) > 2:
        seq=seq[0:2]
    return seq
print(func1([1,2,3,4]))


#题目五
def func2(seq):
    return seq[::2]
print(func2([1,2,3,4,5,6,7]))


#题目六
def func3(dic):
    d={}
    for k,v in dic.items():
        if len(v) > 2:
            d[k]=v[0:2]
    return d
print(func3({'k1':'abcdef','k2':[1,2,3,4],'k3':('a','b','c')}))