在Pandas系列中寻找相邻区域

Question

我想选择值大于1的所有区域，如果它们连接到值大于5的元素。 如果两个值被0分隔，则它们不连接。在

以下数据集

pd.Series(data = [0,2,0,2,3,6,3,0])

输出应该是

^{pr2}$

Answer 1

我自己解决了一个丑陋的方式，见下文。不过，我还是想知道有没有更好的方法来做这件事。在

test_series = pd.Series(data = [0,2,0,2,3,6,3,0])

bool_df = pd.DataFrame(data= [(test_series>1), (test_series>5)]).T 
bool_df.loc[:,0] = (bool_df.loc[:,0])&(~bool_df.loc[:,1])
# make a boolean DataFrame.
# Column 0 is values between 1 and 5, and column 1 is values above 5.
# the resulting boolean series we are looking for is column 1 after it has been modified in the following way.



k=0 # k is an integer that indexes the bool_df values that are less than 1
while k < len(bool_df.loc[bool_df.loc[:,0],0]):
    i = bool_df.loc[bool_df.loc[:,0],0].index[k] # the bool_df index corresponding to k
    if i > 0: # avoid negative indeces
        if bool_df.loc[i-1,1]: # Check if the previous entry had a value above 5
            bool_df.loc[i,1] = True
            k+=1
        else: 
            j=i
            while bool_df.loc[j,0]: # find the end of the streak of 1<values<5.
                j+=1
            bool_df.loc[i:j,1] = bool_df.loc[j,1] # set the whole streak to the value found at the end, either >5 or <1
            k = sum(bool_df.loc[bool_df.loc[:,0],0].index<j) 
    else:
        k+=1