NumPy char | find method
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NumPy's find(~)
method returns the index of the first occurrence of the specified substring in each input string. If not found, -1 is returned.
The index(~)
does the exact same thing as the find(~)
method, but the difference is that index(~)
returns a ValueError
when the input string is not found, whereas find(~)
method returns -1
.
Parameters
1. a
| array_like
The source array.
2. sub
| string
The substring to search for in the source array.
3. start
link | int
| optional
The index to start searching from. By default, start=0.
4. end
link | int
| optional
The index to search until. By default, end is equal to the size of the input array.
Return value
A NumPy array of integer indices.
Examples
Basic usage
np.char.find(["abcd", "def"], "bc")
array([ 1, -1])
Notice how -1
is returned for "def"
since it does not include the substring "bc"
.
Specifying a starting index
np.char.find(["abcd"], "ab", start=1)
array([-1])
Since we are starting from the 1st index, the search is performed on the string "bcd"
, which does not contain the substring "ab"
.
Specifying an ending index
np.char.find(["abcd"], "cd", end=3)
array([-1])
Since we stop our search at the 3rd index (inclusive), the search is performed on the string "abc"
, which does not contain the substring "cd"
.