"""
Line Chart with Percent axis
----------------------------
This example shows how to format the tick labels of the y-axis of a chart as percentages.
"""
# category: line charts
import altair as alt
from vega_datasets import data

source = data.jobs.url

alt.Chart(source).mark_line().encode(
    alt.X('year:O'),
    alt.Y('perc:Q').axis(format='%'),
    alt.Color('sex:N')
).transform_filter(
    alt.datum.job == 'Welder'
)
