编写函数判断字符串是否为纯数字python python判断字符串是否为数字？
python\u5224\u65ad\u5b57\u7b26\u4e32\u662f\u5426\u4e3a\u6570\u5b57\u5224\u5b9a\u662f\u5426\u4e3a\u6570\u5b57\u65b9\u6cd5\u4e00\uff1a
try:
float(s)
return True
exceptValueError:
pass
try:
importunicodedata
unicodedata.numeric(s)
return True
except (TypeError
, ValueError):
pass
return False
\u65b9\u6cd5\u4e8c\uff1a\u666e\u901a\u5341\u8fdb\u5236\u6b63\u5e38\u5904\u7406
\u5bf9\u4e8e\u975e\u5341\u8fdb\u5236\u8fd8\u9700\u8981\u66f4\u590d\u6742\u7684\u65b9\u6cd5\uff0c\u4e0d\u8fc7\u8fd9\u91cc\u4e0d\u8ba8\u8bba\uff0c\u53ea\u8ba8\u8bba\u666e\u901a\u5341\u8fdb\u5236\u6570\u7684\u5f71\u54cd\u3002
\u5341\u8fdb\u5236\u6570\u683c\u5f0f\u4e00\u822c\u6709\u4ee5\u4e0b\u51e0\u79cd\uff08\u6574\u6570\u3001\u5c0f\u6570\u3001\u79d1\u5b66\u8ba1\u6570\u6cd5\uff09\uff1a
+123 [\u7b26\u53f7\u4f4d][\u6570\u5b57]
-123.123 [\u7b26\u53f7\u4f4d][\u5c0f\u6570\u70b9][\u6570\u5b57]
+123E+123 [\u6574\u6570\u6216\u5c0f\u6570][E\u6216\u8005D\uff0c\u5927\u5c0f\u5199\u7686\u53ef][\u6574\u6570]
\u5224\u5b9a\u662f\u5426\u4e3a\u6570\u5b57\u65b9\u6cd5\u4e00\uff1a
try:
float(s)
return True
exceptValueError:
pass
try:
importunicodedata
unicodedata.numeric(s)
return True
except (TypeError
, ValueError):
pass
return False
\u65b9\u6cd5\u4e8c\uff1a\u666e\u901a\u5341\u8fdb\u5236\u6b63\u5e38\u5904\u7406
\u5bf9\u4e8e\u975e\u5341\u8fdb\u5236\u8fd8\u9700\u8981\u66f4\u590d\u6742\u7684\u65b9\u6cd5\uff0c\u4e0d\u8fc7\u8fd9\u91cc\u4e0d\u8ba8\u8bba\uff0c\u53ea\u8ba8\u8bba\u666e\u901a\u5341\u8fdb\u5236\u6570\u7684\u5f71\u54cd\u3002
\u5341\u8fdb\u5236\u6570\u683c\u5f0f\u4e00\u822c\u6709\u4ee5\u4e0b\u51e0\u79cd\uff08\u6574\u6570\u3001\u5c0f\u6570\u3001\u79d1\u5b66\u8ba1\u6570\u6cd5\uff09\uff1a
+123 [\u7b26\u53f7\u4f4d][\u6570\u5b57]
-123.123 [\u7b26\u53f7\u4f4d][\u5c0f\u6570\u70b9][\u6570\u5b57]
+123E+123 [\u6574\u6570\u6216\u5c0f\u6570][E\u6216\u8005D\uff0c\u5927\u5c0f\u5199\u7686\u53ef][\u6574\u6570]
如何用编写函数判断字符串是否为纯数字，下面定义一个只有1行的函数digitall来判断之，测试代码如下7行所示
import re;
a="s123not-only-numbers";
b="1234567"
def digitall(s):return (
True if re.match(r"\d+",s) else False);
print('a:"%s" is all numbers:'%a, digitall(a));
print('b:"%s" is all numbers:'%b, digitall(b));
运行结果
在线调试代码图片
在线调试过程图
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绛旓細js楠岃瘉鏄惁涓烘暟瀛锛屾渶绠鍗曠殑鏂规硶锛1.isNaN鍑芥暟鐨勪娇鐢細function checknum() {if (isNaN(frm.num.value)) {alert("璇疯緭鍏ユ暟瀛");frm.num.focus();return false;} } 2.鏈瀹屾暣鏈绮剧‘鐨勬柟娉曪細"^\\d+$"//闈炶礋鏁存暟锛堟鏁存暟 + 0锛"^[0-9]*[1-9][0-9]*$"銆 //姝ｆ暣鏁"^((-\\d+...
绛旓細璁＄畻杩囩▼锛氬師鍨嬶細 int isdigit(char c)銆傜敤娉曪細#include <ctype.h>銆傚姛鑳斤細鍒ゆ柇瀛楃c鏄惁涓烘暟瀛椼傝鏄庯細褰揷涓烘暟瀛0-9鏃讹紝杩斿洖闈為浂鍊硷紝鍚﹀垯杩斿洖闆躲傝繖涓鍑芥暟鏄鍒ゆ柇鏌愪竴涓瀛楃鏄惁涓烘暟瀛锛屽彲浠ョ敤涓涓瓧绗︽暟缁勬帴鍙楄緭鍏ョ殑瀛楃锛岀劧鍚庡惊鐜垽鏂瘡涓涓瓧绗︽槸鍚︿负鏁板瓧锛屽鏋滃叾涓竴涓笉鏄暟瀛楋紝閭ｄ箞杩斿洖0锛屽惁鍒...
绛旓細鈽呪槄鈽呴兘浠栦滑杩欎箞澶嶆潅锛歩nt check(char *s) /* 瀹氫箟涓涓鍒ゆ柇鏄惁鍏涓烘暟瀛鐨鍑芥暟锛屽叾鍙傛暟涓瀛楃涓s */ {int i,mark=0; /* 瀹氫箟鐢ㄤ簬寰幆鐨勬暣鍨嬪彉閲廼鍜岀敤浜庤褰曠殑鏁村瀷鍙橀噺mark */ for(i=0;s[i];i++) /* 寮濮嬩竴涓釜鍒ゆ柇锛屽鏋渟[i]涓虹┖鍗崇粨鏉熷垽鏂 */ {if((s[i]!='...
绛旓細JS鍒ゆ柇瀛楃涓鍏涓烘暟瀛鏂规硶锛 function CheckMyForm() { var txt = myform.mytext.value; if(checknumber(txt)) { alert("鍙厑璁歌緭鍏ユ暟瀛楋紒"); return false; } return true; }function checknumber(String) { var Letters = "1234567890"; var i; var c; for( i = 0; i < Letters.lengt...
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绛旓細闂锛鍒ゆ柇鏄惁鏄暟瀛楀瓧绗︿覆浣跨敤浠涔鍑芥暟 IsNumeric 鍑芥暟鍙敤浜妫娴鍙橀噺鏄惁涓烘暟瀛鎴栨暟瀛楀瓧绗︿覆銆傚嚱鏁板師鍨嬶細IsNumeric(expression)鍙傛暟锛歟xpression 蹇呴渶锛屽寘鍚暟鍊艰〃杈惧紡鎴栧瓧绗︿覆琛ㄨ揪寮忋傝繑鍥炲硷細濡傛灉鏁翠釜 expression 鐨勮繍绠楃粨鏋滀负鏁板瓧锛屽垯 IsNumeric 杩斿洖 True锛涘惁鍒欒繑鍥 False銆備緥濡傦細Dim Check,Var Var=25.6...
绛旓細java涓鍒ゆ柇瀛楃涓叉槸鍚︿负鏁板瓧鐨勬柟娉:1.鐢↗AVA鑷甫鐨鍑芥暟 public static boolean isNumeric(String str){for (int i = 0; i < str.length(); System.out.println(str.charAt(i));if (!Character.isDigit(str.charAt(i))){return false;} }return true} 2.鐢ㄦ鍒欒〃杈惧紡 棣栧厛瑕乮mport java.util...
绛旓細--鍒ゆ柇姣忎釜瀛楃鏄笉鏄0-9 if ascii(v_tmp) not in (48, 49, 50, 51, 52, 53, 54, 55, 56, 57) then --鏄'.'涓嶈秴杩1娆 if v_tmp = '.' and v_dot = 0 then v_dot := v_dot + 1;null;--绗竴浣嶅彲浠ユ槸'+'鍜'-'elsif v_i = 1 then if v_sign = 0 and (...
