import time
from boto import datapipeline as DP

conn = DP.connect_to_region("us-east-1")
more_dp = True
marker = None
dps = []
while more_dp:
    res = conn.list_pipelines(marker=marker)
    if res.get("hasMoreResults") and res["hasMoreResults"] == True:
        marker = res["marker"]
        dps.extend(res["pipelineIdList"])
    else:
        more_dp = False
        dps.extend(res["pipelineIdList"])

for dp in dps:
    time.sleep(1) # prevent hitting rate limit
    definition = conn.get_pipeline_definition(dp["id"])
    for x in definition["pipelineObjects"]:
        for y in x["fields"]:
            if y.get("key") and y["key"] == "subnetId":
                if y["stringValue"] == "subnet-af36c284":
                    print(dp["id"])