a = ["you", "shall", "not", "pass"]
inot = a.index("not")
print("index of the word 'not' is ",inot)index of the word 'not' is 2Object methods
- Some objects also have some built-in methods that can be called to perform various operations…
- To do that, you type the object or the variable which is pointing to it, add a ‘`.``’, and then type the method.
For example, to find the index of an element of a list:
Sequence methods
Remember: sequences are ordered and subscriptable with integers (the indexes). The methods below thus work for all of these types: lists, tuples and strings.
| Operation | Result |
|---|---|
| x in s | True if an item of s is equal to x, else False |
| x not in s | False if an item of s is equal to x, else True |
| s + t | the concatenation of s and t |
| s * n or n * s | equivalent to adding s to itself n times |
| s[i] | ith item of s, origin 0 |
| s[i:j] | slice of s from i to j |
| s[i:j:k] | slice of s from i to j with step k |
| len(s) | length of s |
| min(s) | smallest item of s |
| max(s) | largest item of s |
| s.index(x[, i[, j]]) | index of the first occurrence of x in s (at or after index i and before index j) |
| s.count(x) | total number of occurrences of x in s |
Unpacking sequences
All sequence types can also be unpacked in multiple variables. For example:
s = ["I", "am", "your", "father"]
a, b, c, d = s
print(a)
print(b)I
ams = "hi!"
ch1, ch2, ch3 = s
print(ch1, ch2, ch3)h i !But careful: you will get an error if you don’t match the length:
a = [1, 2, 3]
v1, v2, v3, v4 = aValueError: not enough values to unpack (expected 4, got 3)