Hands-On Application Development with PyCharm

Unresolved references

Another common problem that PyCharm's code analyzer can detect—and this one is actually an error—is unresolved references. As we mentioned previously, in our example, we are using the sqrt() function from the math module without importing it. The general error extends to any unimported and undeclared API.

To fix this error, you can manually import the function from the math module by typing the import statement into the code. On the other hand, you can take advantage of intention actions by performing the following steps:

1. Move your cursor to where the error is, that is, the math part of print(math.sqrt(4)).
2. A red light-bulb icon will appear shortly at the beginning of the line of code, as shown in the following screenshot. ...