# Giới thiệu kiểu dữ liệu Python

Python hỗ trợ tùy chọn "type hints" (còn được gọi là "type annotations").

Những **"type hints"** hay chú thích là một cú pháp đặc biệt cho phép khai báo <abbr title="ví dụ: str, int, float, bool"> kiểu dữ liệu</abbr> của một biến.

Bằng việc khai báo kiểu dữ liệu cho các biến của bạn, các trình soạn thảo và các công cụ có thể hỗ trợ bạn tốt hơn.

import static com.google.common.primitives.UnsignedBytes.toInt;
import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.primitives.Chars;
import com.google.common.primitives.Ints;
import com.google.common.primitives.Longs;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.Immutable;
import java.io.Serializable;
import java.nio.ByteBuffer;

package com.google.common.cache;

import com.google.caliper.AfterExperiment;
import com.google.caliper.BeforeExperiment;
import com.google.caliper.Benchmark;
import com.google.caliper.Param;
import com.google.common.primitives.Ints;
import java.util.Random;
import java.util.concurrent.atomic.AtomicLong;

/**
 * Single-threaded benchmark for {@link LoadingCache}.
 *
 * @author Charles Fry
 */

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.primitives.Ints;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

   * of the returned array is that of the specified array. If the collection fits in the specified
   * array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the
   * specified array and the size of the specified collection.
   *
   * <p>If the collection fits in the specified array with room to spare (i.e., the array has more

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.primitives.Ints;
import com.google.errorprone.annotations.concurrent.LazyInit;
import java.util.Collection;
import java.util.Map;
import javax.annotation.CheckForNull;

/**

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkPositionIndexes;

import com.google.common.primitives.Chars;
import com.google.common.primitives.Ints;
import com.google.common.primitives.Longs;
import com.google.common.primitives.Shorts;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

/**

   * of the returned array is that of the specified array. If the collection fits in the specified
   * array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the
   * specified array and the size of the specified collection.
   *
   * <p>If the collection fits in the specified array with room to spare (i.e., the array has more

</blockquote>

## Investigation

By using all the previous alternatives I had the chance to learn from all of them, take ideas, and combine them in the best way I could find for myself and the teams of developers I have worked with.

For example, it was clear that ideally it should be based on standard Python type hints.

package com.google.common.io;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Preconditions;
import com.google.common.primitives.Ints;
import com.google.common.primitives.Longs;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.DoNotCall;
import java.io.DataInput;
import java.io.DataInputStream;