Oftentimes you want to find the index of a list-like object. Numpy arrays, for example, do not have a index member function. These get the job done quickly.
Note: these do not raise exceptions, instead they return -1 on error. You should change that if you want different behavior.
Python, 32 lines
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Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | def first_index_gt(data_list, value):
'''return the first index greater than value from a given list like object'''
try:
index = next(data[0] for data in enumerate(data_list) if data[1] > value)
return index
except StopIteration: return - 1
def first_index_lt(data_list, value):
'''return the first index less than value from a given list like object'''
try:
index = next(data[0] for data in enumerate(data_list) if data[1] < value)
return index
except StopIteration: return - 1
def first_index_ne(data_list, value):
'''returns first index not equal to the value from list'''
try:
index = next(data[0] for data in enumerate(data_list) if data[1] != value)
return index
except StopIteration: return - 1
def first_index_et(data_list, value):
'''same as data_list.index(value), except with exception handling
Also finds 'nan' values'''
try:
if type(value) == float and math.isnan(value):
return next(data[0] for data in enumerate(data_list)
if (type(data[1]) in (float, np.float64, np.float32, np.float96)
and math.isnan(data[1])))
else:
return next(data[0] for data in enumerate(data_list) if data[1] == value)
except (ValueError, StopIteration): return - 1
|
