我假设接收一个输入并根据输入是否为有效数字返回 true 或 false。以下是一些示例:
"0" => true
" 0.1 " => true
"abc" => false
"1 a" => false
"2e10" => true
" -90e3 " => true
" 1e" => false
"e3" => false
" 6e-1" => true
" 99e2.5 " => false
"53.5e93" => true
" --6 " => false
"-+3" => false
"95a54e53" => false
我有一个所有有效字符的列表,我决定使用切片符号来查看输入的第 0 个索引中的哪个字符与任何有效字符匹配。但是,代码将输入 9
误读为 false。这是我目前的完整代码。我还没有检查所有条件:
class Solution:
def isNumber(self, s: str) -> bool:
valid_char = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '+', 'e', '.']
str_lst = list(s)
if str_lst[0] in valid_char[0:10]:
return True
else:
return False
最佳答案
我认为最好的方法是使用 try
/except
子句来尝试将字符串转换为 float
:
"0" => true " 0.1 " => true "abc" => false "1 a" => false "2e10" => true " -90e3 " => true " 1e" => false "e3" => false " 6e-1" => true " 99e2.5 " => false "53.5e93" => true " --6 " => false "-+3" => false "95a54e53" => false
让我们用上面的字符串生成一个列表:
l = ["0", " 0.1 ", "abc", "1 a", "2e10", " -90e3 ", " 1e", "e3",
" 6e-1", " 99e2.5 ", "53.5e93", " --6 ", "-+3", "95a54e53"]
def is_number(s):
try:
float(s)
return True
except ValueError:
return False
list(map(is_number, l))
# [True, True, False, False, True, True, False, False, True, False,
# True, False, False, False]
关于python - 检查字符串是否为 float ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/58096501/