関連ワード:  python check if a string a number    python check if a string contains a number    python check if a string has a number    python check if a string is a number or float    python check if a string represents a number    python check if a string starts with a number    python test if a string is a number    python check if a string is a negative number    python check if a string is a hex number    python check if a string is a decimal number