decompress strings

def decompress_string(compressed_str):
    decompressed_str = ""
    i = 0
    while i < len(compressed_str):
        char = compressed_str[i]
        i += 1
        count = 0
        while i < len(compressed_str) and compressed_str[i].isdigit():
            count = count * 10 + int(compressed_str[i])
            i += 1
        decompressed_str += char * (count if count > 0 else 1)
    return decompressed_str

# Example usage
compressed_str = "a3b2c"
decompressed_str = decompress_string(compressed_str)
print(decompressed_str)  # Output: aaabbc