如何将java参数传递给python，从java调用python代码

我创建了简单的python语句 我的_utils.py

def adder(a, b):
    c=a+b
    return c

我想给Java中的python赋值

public class ParameterPy {
public static void main(String a[]){
try{

int number1 = 100;
int number2 = 200;

ProcessBuilder pb = new ProcessBuilder("C:/Python27/python","D://my_utils.py",""+number1,""+number2);
Process p = pb.start();

BufferedReader bfr = new BufferedReader(new InputStreamReader(p.getInputStream()));

System.out.println(".........start   process.........");  
String line = "";     
while ((line = bfr.readLine()) != null){
    System.out.println("Python Output: " + line);
}
System.out.println("........end   process.......");


}catch(Exception e){System.out.println(e);}
}
}

但是，process builder无法在python中将参数值传递给a、b并显示结果。

如何将参数值赋予python？如果数值被计算？如果我将非数字值（如字符串）传递给python，怎么样

def str(myWord):
    if myWord=="OK":
        print "the word is OK."
    else:
        print " the word is not OK."

---

Python

sys

模块通过

sys.argv

提供对任何命令行参数的访问。但参数的类型始终是字符串。以下是我希望如何检查数值的示例：

import sys

print 'Number of arguments:', len(sys.argv), 'arguments.'
print 'Argument List:', str(sys.argv)

def adder(a, b):
    c=a+b
    return c

def is_number(x):
    try:
        float(x)
        return True
    except ValueError:
        return False

p1 = sys.argv[1]
p2 = sys.argv[2]

if is_number(p1) and is_number(p2):
    print "Sum: {}".format(adder(float(p1), float(p2)))
else:
    print "Concatenation: {}".format(adder(p1, p2))

更新：如@cricket_007所述，如果只想检查整数，可以使用

isdigit

。但它不适用于浮动：

>>> "123".isdigit()
True
>>> "12.3".isdigit()
False

---

Python

sys

模块通过

sys.argv

提供对任何命令行参数的访问。但参数的类型始终是字符串。以下是我希望如何检查数值的示例：

import sys

print 'Number of arguments:', len(sys.argv), 'arguments.'
print 'Argument List:', str(sys.argv)

def adder(a, b):
    c=a+b
    return c

def is_number(x):
    try:
        float(x)
        return True
    except ValueError:
        return False

p1 = sys.argv[1]
p2 = sys.argv[2]

if is_number(p1) and is_number(p2):
    print "Sum: {}".format(adder(float(p1), float(p2)))
else:
    print "Concatenation: {}".format(adder(p1, p2))

更新：如@cricket_007所述，如果只想检查整数，可以使用

isdigit

。但它不适用于浮动：

>>> "123".isdigit()
True
>>> "12.3".isdigit()
False

在爪哇

int number1 = 100;
int number2 = 200;
String searchTerm="google";
ProcessBuilder pb = new ProcessBuilder("C:/Python27/python","D://searchTestJava//my_utils.py",""+number1,""+number2,""+searchTerm);
Process p = pb.start();

BufferedReader bfr = new BufferedReader(new InputStreamReader(p.getInputStream()));

System.out.println(".........start   process.........");  
String line = "";     
while ((line = bfr.readLine()) != null){
    System.out.println("Python Output: " + line);

输出结果：

Python Output: a is: 100
Python Output: b is: 200
Python Output: 300
Python Output: google
Python Output:  you get it

在爪哇

int number1 = 100;
int number2 = 200;
String searchTerm="google";
ProcessBuilder pb = new ProcessBuilder("C:/Python27/python","D://searchTestJava//my_utils.py",""+number1,""+number2,""+searchTerm);
Process p = pb.start();

BufferedReader bfr = new BufferedReader(new InputStreamReader(p.getInputStream()));

System.out.println(".........start   process.........");  
String line = "";     
while ((line = bfr.readLine()) != null){
    System.out.println("Python Output: " + line);

输出结果：

Python Output: a is: 100
Python Output: b is: 200
Python Output: 300
Python Output: google
Python Output:  you get it

---

您从进程中获取的输入流可能重复，而不是写入打印语句的输出流。您从进程中获取的输入流可能重复，而不是写入打印语句的输出流。python字符串类不提供

isdigit

？为什么尝试强制转换该值？

isdigit（）

如果只需要整数，也可以。但是对于

float

，它返回

False

。python字符串类不提供

isdigit

？为什么尝试强制转换该值？

isdigit（）

如果只需要整数，也可以。但是对于

float

，它返回

False

。