pymseed 0.0.3

A Python package for reading and writing miniSEED formatted data

pymseed - a Python package to read and write miniSEED formatted data

The pymseed package supports reading and writing of miniSEED formatted data. Both miniSEED version 2 (defined in the SEED standard) and miniSEED version 3 are supported.

The package is uses the C-language libmseed for most of the data format and manipulation work.

Installation

The releases should be installed directly from PyPI with, for example, pip install pymseed.

If using numpy features use optional dependency "numpy" or install it independently e.g. pip install pymseed[numpy].

For package develop use optional dependency "dev" for needed dependencies e.g. pip install pymseed[dev].

Example usage

Working programs for a variety of use cases can be found in the examples directory of the repository.

Read a file and print details from each record:

from pymseed import MS3Record, TimeFormat

input_file = "examples/example_data.mseed"

for record in MS3Record.from_file(input_file):
    # Print values directly
    print(f'   SourceID: {record.sourceid}, record length {record.reclen}')
    print(f' Start Time: {record.starttime_str(timeformat=TimeFormat.ISOMONTHDAY_SPACE_Z)}')
    print(f'    Samples: {record.samplecnt}')

    # Alternatively, use the library print function
    record.print()

Read a file into a trace list and print the list:

from pymseed import MS3TraceList

traces = MS3TraceList.from_file("examples/example_data.mseed")

# Print the trace list using the library print function
traces.print(details=1, gaps=True)

# Alternatively, traverse the data structures and print each trace ID and segment
for traceid in traces:
    print(traceid)

    for segment in traceid:
        print('  ', segment)

Writing miniSEED requires specifying a "record handler" function that is a callback to consume, and do whatever you want, with generated records.

Simple example of writing multiple channels of data:

import math
from pymseed import MS3TraceList, timestr2nstime

# Generate sinusoid data, starting at 0, 45, and 90 degrees
data0 = list(map(lambda x: int(math.sin(math.radians(x)) * 500), range(0, 500)))
data1 = list(map(lambda x: int(math.sin(math.radians(x)) * 500), range(45, 500 + 45)))
data2 = list(map(lambda x: int(math.sin(math.radians(x)) * 500), range(90, 500 + 90)))

traces = MS3TraceList()

output_file = "output.mseed"
sample_rate = 40.0
start_time = timestr2nstime("2024-01-01T15:13:55.123456789Z")
format_version = 2
record_length = 512

# Add generated data to the trace list
traces.add_data(sourceid="FDSN:XX_TEST__B_S_1",
                data_samples=data0, sample_type='i',
                sample_rate=sample_rate, start_time=start_time)

traces.add_data(sourceid="FDSN:XX_TEST__B_S_2",
                data_samples=data1, sample_type='i',
                sample_rate=sample_rate, start_time=start_time)

traces.add_data(sourceid="FDSN:XX_TEST__B_S_3",
                data_samples=data2, sample_type='i',
                sample_rate=sample_rate, start_time=start_time)

traces.to_file(output_file,
               format_version=format_version,
               max_reclen = record_length)

Package design rationale

The package functionality and exposed API are designed to support the most common use cases of reading and writing miniSEED data using libmseed. Extensions of data handling beyond the functionality of the library are out-of-scope for this package. Furthermore, the naming of functions, classes, arguments, etc. often follows the naming used in the library in order to reference their fundamentals at the C level if needed; even though this leaves some names distinctly non-Pythonic.

In a nutshell, the goal of this package is to provide just enough of a Python layer to libmseed to handle the most common cases of miniSEED data without needing to know any of the C-level details.

License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Copyright (C) 2025 EarthScope Data Services