PyQt:How do i set different header sizes for individual headers?

There are a few methods of the QHeaderView class that will probably do what you want. The simplest is:

table.horizontalHeader().setStretchLastSection(True)

This will ensure that the last column is automatically resized to fit the available space in the table, leaving the width of the other columns as they are (and resizable by the user).

Alternatively, there are methods for setting the ResizeMode of the columns.

For Qt5:

table.setColumnWidth(1, 80)
table.horizontalHeader().setSectionResizeMode(0, QHeaderView.Stretch)

For Qt4:

table.setColumnWidth(1, 80)
table.horizontalHeader().setResizeMode(0, QHeaderView.Stretch)

This will fix the width of the second column, and ensure the first column is automatically resized to fill the remaining space (but preventing any other resizing by the user).

the best solution for this, in Qt5 you have to use setSectionResizeMode instead of setResizeMode:

tabv = QTableView()
tabv.horizontalHeader().setSectionResizeMode(QHeaderView.Stretch)

or

tabv.horizontalHeader().setSectionResizeMode(1)