Each of these data containers can be written to and read from disk using the FIF file format, which is readable from the MNE C code and the MNE-Matlab toolbox. These containers share some common attributes such as ch_names, which is a Python list containing the names of all of the channels, and an info attribute which is a modified Python dictionary storing all the metadata about the recordings. This attribute is commonly called the measurement information. For example, the sfreq key in the info dictionary, accessed with info['sfreq'] syntax, is the sampling frequency; the channel types and positions are available in info['chs']; the positions of the head digitization points used for coregistration are contained in info['dig']; and info['bads'] stores the list of bad channels. The info attribute can be used to conveniently do some channel selection by type (e.g., gradiometers, magnetometers, EEG), general position (e.g., right temporal channels), or simply by channel names. These convenience functions in MNE-Python are known as pick functions, and they start with pick_ (e.g., pick_types to select by channel type). Other standard data structures
