Accessing a Series

You can reach values in a Series in two ways:

• positional index: the position, starting at 0;
• labelled index: the labels you gave.

Slicing works with both, but with one important difference:

• a positional slice excludes the end position: s[1:3] gives the values at positions 1 and 2;
• a label slice includes the end label: s['Jan':'Mar'] gives Jan, Feb and Mar.

s[::-1] gives the series in reverse order. Slices can also be used to change values: s[1:3] = 0.

Useful attributes: name (the series' name), index.name, values (the values as an array), size (number of values) and empty (True if there are no values).

Useful methods: head(n) and tail(n) show the first or last n values (5 if n is not given), and count() counts the values that are not NaN (not missing). Positions exclude the end; labels include it.