Installation and Quick Start

npTDMS is available from the Python Package Index, so the easiest way to install it is by running:

pip install npTDMS

There are optional features available that require additional dependencies. These are hdf for hdf export, pandas for pandas DataFrame export, and thermocouple_scaling for reading files that use thermocouple scalings. You can specify these extra features when installing npTDMS to also install the dependencies they require:

pip install npTDMS[hdf,pandas,thermocouple_scaling]

Alternatively, after downloading the source code you can extract it and change into the new directory, then run:

python install

Typical usage when reading a TDMS file might look like:

from nptdms import TdmsFile

tdms_file ="path_to_file.tdms")
for group in tdms_file.groups():
    group_name =
    for channel in group.channels():
        channel_name =
        # Access dictionary of properties:
        properties =
        # Access numpy array of data for channel:
        data = channel[:]
        # Access a subset of data
        data_subset = channel[100:200]

Or to access a channel by group name and channel name directly:

group = tdms_file[group_name]
channel = group[channel_name]

The method reads all data into memory immediately. When you are working with large TDMS files or don’t need to read all channel data, you can instead use This is more memory efficient but accessing data can be slower:

    channel = tdms_file[group_name][channel_name]
    channel_data = channel[:]

npTDMS also has rudimentary support for writing TDMS files. Using npTDMS to write a TDMS file looks like:

from nptdms import TdmsWriter, ChannelObject
import numpy

with TdmsWriter("path_to_file.tdms") as tdms_writer:
    data_array = numpy.linspace(0, 1, 10)
    channel = ChannelObject('Group', 'Channel1', data_array)