chapter 7: TypeError: 'NoneType' object is not iterable error about hands-on-exploratory-data-analysis-with-python

[sureshHARDIYA]

Seems like you are using latest version of sns. The syntax is changed. You can fix it like:
sns.countplot(titanic, x="Sex", ax = ax[1])

[gokcenazakyol]

But when I change the line like this:
sns.countplot(titanic, x="Sex", ax = ax[1])
The graph of this code is not the same as the original graph that is before.

[sureshHARDIYA]

Its same graph, just removed some labels. You can read how to adapt labels and color from seaborn documentation.