countplot
The countplot function can be used to represent the number of observations of a categorical variable for each group with bars.
import seaborn as sns
data = ["A", "A", "B",
"B", "B", "C"]
# Count plot
sns.countplot(x = data)

Horizontal count plot
In case you want to create an horizontal count plot you will need to pass your data to the y argument, instead of x.
import seaborn as sns
data = ["A", "A", "B",
"B", "B", "C"]
# Count plot
sns.countplot(y = data)


Dodged count plot
In addition, if you have another categorical variable representing subgroups you can input it to the hue argument, as shown below. Set dodge = False in case you want to overplot the bars for each group.
import seaborn as sns
data = ["A", "A", "B", "A",
"B", "B", "C", "C"]
group = ["G1", "G1", "G2", "G2",
"G1", "G2", "G1", "G2"]
# Count plot
sns.countplot(x = data, hue = group)
Color saturation
The saturation of the colors of the bars is 0.75 by default. However, you can make use of the saturation argument to change it, being 0 desaturated and 1 fully saturated.
import seaborn as sns
data = ["A", "A", "B",
"B", "B", "C"]
# Count plot
sns.countplot(x = data, saturation = 1)

Color palette
If you want to override the default color palette you can change it with the palette argument, as in the example below.
import seaborn as sns
data = ["A", "A", "B",
"B", "B", "C"]
# Count plot
sns.countplot(x = data, palette = "Set1")

Same color for all the bars
You can also set the same color for all the bars passing a named color to the color argument of the function.
import seaborn as sns
data = ["A", "A", "B",
"B", "B", "C"]
# Count plot
sns.countplot(x = data,
color = "lightblue")

Border color
Finally, you can also modify the colors of the borders for each bar, setting a color or a vector of colors with edgecolor.
import seaborn as sns
data = ["A", "A", "B",
"B", "B", "C"]
# Count plot
sns.countplot(x = data,
edgecolor = "black")

See also