如何在python中使用变量“构建”字符串

如何解决如何在python中使用变量“构建”字符串

我对python相对较新，因为我来自Java背景。如何在python中构建字符串？在Java中，我只会使用+=运算符。在python中，它似乎不起作用，因此我尝试使用逗号。现在显然当我执行type(summary)时，我得到了元组。而且summary的打印效果不好。

我的代码

summary = "You had",count_lowercase_alpha,"lowercase,"
summary+= count_uppercase_alpha,"uppercase,"
summary+= count_numeric,"numerics,and"
summary+= count_special_chars,"special characters in your password"
print(summary)

它打印什么

('You had',2,'lowercase,','uppercase,'numerics,and','special characters in your password')

我希望它像这样打印

您的密码中有2个小写字母，0个大写字母，0个数字和0个特殊字符

* p.s。我是Stackoverflow的新手，我很好。 *

解决方法

这是一个基本问题，我强烈建议您在Stackoverflow中提问之前先搜索有关python基础的更多信息。但正如您所问的，我使您的代码对python可读：

count_lowercase_alpha = 2
count_uppercase_alpha = 0
count_numeric = 0
count_special_chars = 0

summary = "You had "+ str(count_lowercase_alpha)+ " lowercase,"
summary+= " "+str(count_uppercase_alpha)+ " uppercase,"
summary+=" " + str(count_numeric)+ " numerics,and"
summary+=" " + str(count_special_chars)+ " special characters in your password"
print(summary)

输出

You had 2 lowercase,0 uppercase,0 numerics,and 0 special characters in your password

,

python中的逗号运算符创建一个元组。元组有点类似于Java数组。

此表达式的计算结果为元组：

RewriteRule ^index\.html$ - [L]
 RewriteCond %{REQUEST_FILENAME} !-f
 RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.html [L]

要使其成为字符串，您应该像Java一样将加号连接起来

"You had",count_lowercase_alpha,"lowercase,"

其余代码似乎正确。

,

或者可以使用f strings（或.format()方法）进行串联

name = "Ironkey"
age = "12345"

string = f"{name} is {age} years old!?"

,

+和+=运算符可用于字符串，只要两个操作数实际上都是字符串即可（这意味着在添加它们之前，需要先用str对其进行转换）。

做这种事情的更简单方法是f字符串，它使您可以在字符串文字内插任意表达式（根据需要自动将内插值转换为字符串）：

print(f"You had {count_lowercase_alpha} lowercase,{count_uppercase_alpha} uppercase,{numerics} numerics,and {count_special_chars} special characters in your password.")

您可以在代码的多行中分割字符串文字（包括f字符串），如下所示：

print(
    f"You had {count_lowercase_alpha} lowercase,"
    f"{count_uppercase_alpha} uppercase,"
    f"{numerics} numerics,"
    f"and {count_special_chars} special characters in your password."
)

,

,是用于创建元组的运算符。在变量和字符串之间添加+，以将它们组合在一起。但是要小心，变量必须是字符串或转换为字符串。

summary = "You had" + str(count_lowercase_alpha) + "lowercase" + str(count_uppercase_alpha) + "uppercase," + str(count_numeric) + "numerics,and " + str(count_special_chars) + "special characters in your password"
print(summary)