aes(*args, **kwargs)

Create aesthetic mappings


x : str | array_like | scalar

x aesthetic mapping

y : str | array_like | scalar

y aesthetic mapping

**kwargs : dict = {}

Other aesthetic mappings


Only the x and y aesthetic mappings can be specified as positional arguments. All the rest must be keyword arguments.

The value of each mapping must be one of:

  • str

     import pandas as pd
     import numpy as np
     arr = [11, 12, 13]
     df = pd.DataFrame({
         "alpha": [1, 2, 3],
         "beta": [1, 2, 3],
         "gam ma": [1, 2, 3]
     # Refer to a column in a dataframe
     ggplot(df, aes(x="alpha", y="beta"))
  • array_like

    # A variable
    ggplot(df, aes(x="alpha", y=arr))
    # or an inplace list
    ggplot(df, aes(x="alpha", y=[4, 5, 6]))
  • scalar

    # A scalar value/variable
    ggplot(df, aes(x="alpha", y=4))
    # The above statement is equivalent to
    ggplot(df, aes(x="alpha", y=[4, 4, 4]))
  • String expression

    ggplot(df, aes(x="alpha", y="2*beta"))
    ggplot(df, aes(x="alpha", y="np.sin(beta)"))
    ggplot(df, aes(x="df.index", y="beta"))
    # If `count` is an aesthetic calculated by a stat
    ggplot(df, aes(x="alpha", y=after_stat("count")))
    ggplot(df, aes(x="alpha", y=after_stat("count/np.max(count)")))

    The strings in the expression can refer to;

    1. columns in the dataframe
    2. variables in the namespace
    3. aesthetic values (columns) calculated by the stat

    with the column names having precedence over the variables. For expressions, columns in the dataframe that are mapped to must have names that would be valid python variable names.

    This is okay:

    # "gam ma" is a column in the dataframe
    ggplot(df, aes(x="df.index", y="gam ma"))

    While this is not:

    # "gam ma" is a column in the dataframe, but not
    # valid python variable name
    ggplot(df, aes(x="df.index", y="np.sin(gam ma)"))

aes has 2 internal methods you can use to transform variables being mapped.

  1. factor - This function turns the variable into a factor. It is just an alias to pandas.Categorical:

    ggplot(mtcars, aes(x="factor(cyl)")) + geom_bar()
  2. reorder - This function changes the order of first variable based on values of the second variable:

    df = pd.DataFrame({
        "x": ["b", "d", "c", "a"],
        "y": [1, 2, 3, 4]
    ggplot(df, aes("reorder(x, y)", "y")) + geom_col()

The group aesthetic

group is a special aesthetic that the user can map to. It is used to group the plotted items. If not specified, it is automatically computed and in most cases the computed groups are sufficient. However, there may be cases were it is handy to map to it.

See Also


For how to map aesthetics to variable calculated by the stat


For how to alter aesthetics after the data has been mapped by the scale.


For how to map to evaluate the mapping to aesthetics at more than one stage of the plot building pipeline.


import pandas as pd
import numpy as np

from plotnine import ggplot, aes, geom_point


Mapping variables to the visual properties of a plot.

df = pd.DataFrame({
    "col1": np.arange(11),
    "col2": np.arange(11)

    ggplot(df, aes(x="col1", y="col2"))
    + geom_point()

    ggplot(df, aes(x="col1", y="col2 ** 2"))
    + geom_point()

    ggplot(df, aes(x="col1", y="np.square(col2)"))
    + geom_point()

The first two positional arguments are x and y aesthetics. Any other aesthetic must be mapped with a keyword argument.

    ggplot(df, aes("col1", "np.square(col2)", color="col2"))
    + geom_point(size=3)

Source: aes