在Elixir中,如何检查Python中的类型:
>>> a = "test"
>>> type(a)
<type 'str'>
>>> b =10
>>> type(b)
<type 'int'>
我在Elixir中读到了类型检查器,例如'is_bitstring','is_float','is_list','is_map'等,但如果您不知道该类型是什么呢？
在python的nosetests中,您可以通过调用它的类然后调用测试名来指定运行一个测试,我们如何使用Elixir的ExUnit执行此操作？
如何检查Scala中是否存在类似于Python的路径/文件？以下示例:
os.path.exists("/home")
Out[4]: True
这有什么问题:
fn main() {
let word: &str = "lowks";
assert_eq!(word.chars().rev(), "skwol");
}
我收到这样的错误:
error[E0369]: binary operation `==` cannot be applied to type `std::iter::Rev<std::str::Chars<'_>>`
--> src/main.rs:4:5
|
4 | assert_eq!(word.chars().rev(), "skwol");
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: an implementation of `std::cmp::PartialEq` might be missing for `std::iter::Rev<std::str::Chars<'_>>`
= note: this error originates in a macro outside of the current crate
这样做的正确方法是什么？
说我有一个函数的定义:
def rename(src, dst) do
<do rename>
end
在我的Elixir库中,我可以在同一个库中创建:
alias rename, as: mv
那么当用户可以在我的库中使用重命名和mv函数时？
在我调用自定义命令之后，我想在我的 makefile 中调用另一个目标：
first_target:
do_some_stuff
second_target:
call some command
first_target
当我像上面那样做时，它抱怨找不到 first_target 命令。我该怎么做呢？
这是我的目录结构:
lowks@lowkster ~/src/rustlang/gettingrusty $ tree .
.
??? Cargo.lock
??? Cargo.toml
??? foo.txt
??? src
? ??? boolean_example.rs
? ??? function_goodbye_world.rs
? ??? listdir.rs
? ??? looping.rs
? ??? main.rs
? ??? pattern_match.rs
? ??? write_to_file.rs
??? target
??? build
??? deps
??? examples
??? gettingrusty
??? native
6 directories, 11 files
当我运行'货物构建'时,它似乎只是构建main.rs.我该如何更改Cargo.toml以构建其余文件？
警告:去新手.我有这样的功能:
package main
import "flag"
import "fmt"
func print_out_type(x anything) string {
switch v := x.(type) {
case string:
return "A string"
case int32:
return "An Integer"
default:
return "A default"
}
}
func main() {
wordPtr := flag.String("argument1", "foo", "a String")
numPtr := flag.Int("argument2", 42, "an Integer")
flag.Parse()
fmt.Println("word: ", *wordPtr)
fmt.Println("number: ", *numPtr)
}
我试图根据类型返回不同类型的字符串.我只是陷入了如何编写一个接受不同类型参数的函数的问题.任何帮助表示赞赏.
我的 conda 导出是这样完成的：conda env export --file environment.yml -n djangoenv
文件本身如下所示：
\n\nname: djangoenv\nchannels:\n- bioconda\n- anaconda-cluster\n- defaults\ndependencies:\n- anaconda-cluster::python-apt=0.8.5=py27_0\n- auto::pyumpf=0.1.1=py27_0\n- binstar::binstar=1.3.1=py27_0\n- bioconda::httplib2=0.9.2=py27_0\n- clyent=1.2.2=py27_0\n- conda-forge::backports.shutil_get_terminal_size=1.0.0=py27_0\n- conda-forge::ca-certificates=2016.2.28=0\n- conda-forge::ipython=4.2.0=py27_0\n- conda-forge::pexpect=4.1.0=py27_0\n- conda-forge::pickleshare=0.7.2=py27_0\n- conda-forge::ptyprocess=0.5.1=py27_0\n- conda-forge::python-pathlib2=2.1.0=py27_0\n- conda-forge::traitlets=4.2.1=py27_0\n- dateutil=2.4.1=py27_0\n- decorator=4.0.9=py27_0\n- ecdsa=0.13=py27_0\n- ipython_genutils=0.1.0=py27_0\n- jinja2=2.8=py27_0\n- kbroughton::ansible=2.0.0.2=py27_0\n- markupsafe=0.23=py27_0\n- openssl=1.0.2h=0\n- paramiko=1.16.0=py27_0\n- pip=8.1.1=py27_1\n- psycopg2=2.6.1=py27_1\n- pycrypto=2.6.1=py27_0\n- python=2.7.11=0\n- pytz=2016.4=py27_0\n- pyyaml=3.11=py27_1\n- readline=6.2=2\n- requests=2.10.0=py27_0\n- setuptools=20.7.0=py27_0\n- simplegeneric=0.8.1=py27_0\n- six=1.10.0=py27_0\n- sqlite=3.9.2=0\n- tk=8.5.18=0\n- travis::ansible-shell=0.0.2=py27_0\n- wheel=0.29.0=py27_0\n- yaml=0.1.6=0\n- zlib=1.2.8=0\n- pip:\n - anaconda-client==1.3.1\n - ansible==2.0.0.2\n - ansible-lint==2.3.3\n - ansible-shell==0.0.2\n - backports.shutil-get-terminal-size==1.0.0\n - coverage==4.0.3\n - django==1.8\n - django-angular==0.7.15\n - django-countries==3.4.1\n - django-easy-pdf==0.1.0\n - django-money==0.7.4\n …我正在开发一些不需要在App Store上的东西,所以我没有使用私有API来满足我的需求的问题我正在尝试使用MobileWiFi. framework to read the RSSI value for the wireless network the phone is currently connected to. I've included thehttps://github.com/Cykey/ios-reversed -headers/tree/c613e45f3ee5ad9f85ec7d43906cf69ee812ec6a/MobileWiFi`标题并使用桥接头将它们包含在我的swift项目中并编写如下代码.请原谅,我是新手.
import SystemConfiguration.CaptiveNetwork
typealias _WiFiManagerClientCreate = @convention(c) (CFAllocator, CInt) -> UnsafeRawPointer
typealias _WiFiManagerClientCopyDevices = @convention(c) (UnsafeRawPointer) -> CFArray
typealias _WiFiDeviceClientCopyProperty = @convention(c) (UnsafeRawPointer, CFString) -> CFPropertyList
if let libHandle = dlopen (Paths.ipConfiguration, RTLD_LAZY) {
result = libHandle.debugDescription
let _createManagerPtr = dlsym(libHandle, "WiFiManagerClientCreate")
let _clientCopyDevicesPtr = dlsym(libHandle, "WiFiManagerClientCopyDevices")
let _clientCopyPropertyPtr = dlsym(libHandle, "WiFiDeviceClientCopyProperty")
if (_createManagerPtr != nil) …