python 字典遍历

1. 使用python3.4
   遍历字典，将value==2的改为value=1

def value2to1(mydict):    for k,v in mydict.items():        if(v==2):            mydict[k]=1;def printDict(mydict):    for k,v in mydict.items():        print("mydict[%s]:%s" %(k,v))    print();a = {'k1':2, 'k2':3, 'k3':1, 'k4':2};if __name__== '__main__':    printDict(a);    value2to1(a);    printDict(a);