Slice Dataframe At Specific Points And Plot Each Slice

I am new to programming and Pythone could you help me? I have a data frame which look like this. d = {'time': [4, 10, 15, 6, 0, 20, 40, 11, 9, 12, 11, 25], 'value': [0, 0, 0,

Solution 1:

EDIT:

Here's a simpler way of handling my first answer (thanks to @aneroid for the suggestion).

Get the indices where value==100 and add +1 so that these land at the bottom of each slice:

indices = df.index[df['value'] == 100] + 1

Then use numpy.split (thanks to this answer for that method) to make a list of dataframes:

df_list = np.split(df, indices)

Then do your plotting for each slice in a for loop:

fordfin df_list:
     --- plot based on df here ---

VERBOSE / FROM SCRATCH METHOD:

You can get the indices for where value==100 like this:

indices = df.index[df.value==100]

Then add the smallest and largest indices in order to not leave out the beginning and end of the df:

indices = indices.insert(0,0).to_list()
indices.append(df.index[-1]+1)

Then cycle through a while loop to cut up the dataframe and put each slice into a list of dataframes:

i = 0
df_list = []
while i+1 < len(indices):
    df_list.append(df.iloc[indices[i]:indices[i+1]])
    i += 1

Solution 2:

I already solved the problem using for loop, which can be used to slice and plot at the same time without using np.split function, as well as maintain the data structure. Thanks to the previous answer by @k_n_c, it helps me improve it.

slices = df.index[df['score'] == 100]
slices = slices + 1

slices = np.insert(slices, 0,0, axis=0)
slices = np.append(slices,df.index[-1]+1)

prev_ind = 0
for ind in slices:
    temp = df.iloc[prev_ind:ind,:] 
    plt.plot(temp.time, temp.score)
    prev_ind = ind
plt.show()