def check_environment_variable(env_var_name):
"""Check if the given environment variable exists."""
log.info("Checking: {e} environment variable existence".format(
e=env_var_name))
if env_var_name not in os.environ:
log.failure("Fatal: {e} environment variable has to be specified"
.format(e=env_var_name))
sys.exit(1)
else:
log.success("ok")
from fastlog import log
log.setLevel(log.DEBUG)
log.info("log.info")
log.success("log.success")
log.failure("log.failure")
with log.indent():
log.debug("log.debug")
log.warning("log.warning")
log.separator()
log.hexdump(list(map(chr, range(256))))