convert to is_single_string() or rename is_single_integer/float/number()

[todo]

deep-clustering-toolbox/deepclustering/utils/type_check.py

Lines 124 to 129 in f9e3561

	# TODO convert to is_single_string() or rename is_single_integer/float/number()
	def is_string(val):
	"""
	Checks whether a variable is a string.
	Parameters

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This issue was generated by todo based on a TODO comment in f9e3561. It's been assigned to @jizongFox because they committed the code.